Type.—Lectotype, USNM 7855; alcoholic (sex undetermined); obtained from the Río Grande near Brownsville, Texas, in the course of the Mexican Boundary Survey under the command of Colonel Wm. H. Emory.Range.—Southwestern United States and northern México; the Río Grande drainage in Texas, New Mexico and northern México; the Río San Fernando and Río Purificación drainages in northeastern México; the Colorado River drainage in Arizona, New Mexico, and southern Nevada (see map,Fig. 19).Diagnosis.—Juvenal pattern of white dots, not encircled with dusky or blackish ocelli, confined to posterior third of carapace; pale rim of carapace conspicuously widened, four to five times wider posteriorly than laterally; a dark triangle in front of eyes, base line connecting anterior margins of orbits; pale postocular stripe interrupted leaving conspicuous pale, usually dark-bordered, blotch just behind eye.Description.—Plastral length of smallest hatchling, 2.5 centimeters (USNM 7632); of largest male, 13.0 centimeters (KU 2914, 3125, 3150); of largest female, 22.0 centimeters (TNHC 8023, 8104).Carapace pale brownish or tan, lacking whitish dots on anterior half; whitish dots confined to posterior third of carapace, sometimes lacking posteriorly, especially on juveniles; small, blackish dots rarely occurring on surface of carapace, usually confined to margins when present; pale rim of carapace four to five times wider posteriorly than laterally.Pattern on snout rarely variable, consisting of pale stripes extending forward from eyes that have only their outer borders darkened and a straight or slightly curved, dark line that connects anterior margins of orbits; few, if any, dark markings in subocular and postlabial region; pattern on side of head having few contrasting marks, often of nearly uniform coloration; postocular stripe usually interrupted; anterior segment of postocular stripe just behind eye usually dark-bordered; posterior segment usually not dark-bordered or sharply distinguished from background; pattern on dorsal parts of soft parts of body contrasting, of relatively small dark marks; dark streaks often coincident with digits.Underparts whitish, occasionally having blackish dots or smudges on posterior part of carapace, in region of bridge, or on lateral parts of chin and throat; few dark marks often on webbing of limbs and on palms and soles.Small, flattened or wartlike, tubercles that occasionally have sharp tips along anterior edge of carapace on adult males; tubercles flattened, scarcely elevated, never conical along anterior edge of carapace on large females; whitish, knoblike tubercles often present posteriorly in middle of carapace and in nuchal region on large females; mottled and blotched pattern sometimes contrasting on carapace of large females; whitish dots of juvenal pattern often visible through overlying blotched pattern of large females.[511]Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.68, and exceeding 7.0 centimeters, 5.19; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.17, and exceeding 8.5 centimeters, 1.27; mean CL/PCW, 2.18; mean HW/SL, 1.43; mean CL/PL, 1.37.Variation.—Ten topotypes (six males, three females, one juvenile) from Brownsville, Texas (BCB 7465-73, 7564), have the following characteristics: pale rim widened posteriorly as described above; females (plastral lengths 9.8, 10.2 and 11.7 cm.) having blackish marks in pale rim, which are absent in males of corresponding size; interrupted postocular stripe with pale blotch behind eye; postocular pale blotch having blackish borders or not; dark triangular mark on snout in front of eyes; white dots present only on posterior third of carapace; carapace of females grayish, blotched pattern not contrasting; carapace of males paler, greenish-gray; undersurface immaculate except 7468 and 7472 that have blackish flecks at bridge and, on 7472, blackish marks that extend posteriorly onto ventral surface of carapace; tubercles along anterior edge of carapace flattened and rounded in adult males, more knoblike in females; largest specimen, BCB 7472, female, plastron 11.7 centimeters long.T. s. emoryivaries more than any other subspecies ofTrionyx spinifer. A large series of males and females (KU) from the Salt River (Colorado River drainage), near Phoenix, Arizona, is characterized by many adult males having indistinct white dots on posterior half of carapace; blotching on carapace of females of contrasting lichenlike figures, but usually non-contrasting and pale brownish or tan; pale rim of carapace distinct from ground color of carapace in largest female (KU 2905, plastron 21.5 cm. in length), but having dark or dusky markings: dark interorbital stripe often lacking. AMNH 58370 (Nevada) and UMMZ 92006 (Arizona) also have the dark line connecting the anterior margins of the orbits interrupted; seemingly the dark interorbital line is most often interrupted in those softshells inhabiting the Colorado River system of Nevada and Arizona.Other variant individuals are: TU 14453.2, 14462 and 3696 having the plastron extending slightly farther forward than the carapace, thus resemblingT. ferox; UMMZ 54021 and CNHM 39999, hatchlings, lacking distinct whitish dots on posterior half of carapace; UI 43509 and KU 39991 having stained (brown or blackish) claws; and, CNHM 6810, an adult male, lacking a spinose (sandpapery) carapace. I am unable to discern geographic variation in these or other characters.The ground color of the carapace on some individuals from the Pecos River (TU, Terrell County, Texas) is grayish and in contrast with the pale rim (Pl. 44). UI 43509 from the Río Florida, La Cruz, Chihuahua, a female, has a dark brownish carapace with little evidence of a blotched pattern except on the pale rim of the carapace. A female and adult male from the Río Sabinas, Coahuila (MSU 905-06), also show considerable darkening on the dorsal surfaces; the pale rim is evident but not in sharp contrast to the coloration of the carapace. Notes taken on the freshly-killed Sabinas individuals are: male—carapace olive-gray; dorsal surface of soft parts of body olive-green to grayish, a bright yellow suffusion on limbs and neck; female—carapace and soft parts of body dark olive, laterally pale yellow; the plastron extends slightly farther forward than the carapace in both sexes.Notes on coloration (judged to be the most common or "normal" type)[512]of livingemoryifrom the Río Mesquites, central Coahuila, are: Adult male (KU 53753)—pale rim butterscotch yellow; marginal line blackish; whitish dots on pale brown or tan carapace; soft parts of body olive or olive-green, slightly darker on head and paler (yellowish) on hind limbs; pale areas on side of head pale yellow, having tint of orange on neck; ventral surface white, yellow laterally on neck. Adult female (KU 53754)—carapace having contrasting blotched and mottled pattern of pale browns and tans; soft parts of body olive brown, darker brown blotching on head; dorsal surface of limbs olive-green having pale areas lemon yellow and webbing butterscotch yellow; side of neck and head, chin and throat pale lemon yellow; ventral surface white having slight red tinge to groin and soft parts posteriorly; underside of carapace near edge pale yellow.Softshells from the Río Grande in the Big Bend region of Texas, and the Río Conchos in Chihuahua differ from other specimens ofemoryi. Fifteen adult males, KU 51187-201 (no females in sample), were taken from the mouth of the Río San Pedro at Meoquí, Chihuahua (see KU 51194,Pl. 44). They are noteworthy because of a conspicuous orange or orange-yellow on the side of the head. Another relatively consistent character is the blackish tip of snout (excepting 51199), although the degree (palest on 51190) and extent of pigmentation posteriorly on the snout is variable. Eleven males, KU 51175-85, from approximately 100 miles northeastward in the Río Conchos near Ojinaga, Chihuahua, also have the bright orange on the side of the head; the tip of the snout is not blackish, although in some it is slightly darkened. Three females, KU 51174, 51186 (from Ojinaga) and 51173 (from 8 mi. S, 16 mi. W Ojinaga), lack the orange on the side of the head; KU 51186 has a plastral length of 8.0 centimeters, whereas the other two females have the same plastral length of 16.5 centimeters (larger than any male). Nineteen adult males, KU 51965-72, 51980-90, from the Río Grande near Lajitas also have the orangish coloration on the side of the head, whereas twenty females, KU 51954-64, 51973-79, 51991-92 (three smaller than largest male) lack the coloration. The tip of the snout is not blackish on any turtle in the series from Lajitas. The smallest female, from Lajitas, having a plastral length of 6.9 centimeters, has a mottled carapace.The orange of males is most conspicuous in the pale postocular and postlabial areas; the stripes of the snout (distally) and the color of the neck at its juncture with the immaculate ventral surface are orange-yellow. The orange coloration is confined to males (all examined were sexually mature) and is probably not of seasonal occurrence (see comments under secondary sexual variation). I have not noticed this coloration in other males of the subspeciesemoryi; however, long-preserved males might be expected to lack the orange color; the specimens mentioned above were initially preserved in alcohol. KU 51179 (plastral length 8.2 cm., from Ojinaga) is the smallest sexually mature male of the speciesspiniferthat I have seen. Another character of note is the generally greater development of the plastral callosities (resemblingmuticus) than in other subspecies ofspiniferor specimens ofemoryi; three small adult males (KU 51177, 51990, 51987, plastral length 9.3, 9.9 and 9.1 cm., respectively) have large hyoplastral and hypoplastral callosities that appear to touch medially, and callosities on the epiplastron and both preplastra.On July 8, 1953, an adult male ofT. spiniferwas removed from a hoop-net set in the Río Purificación at Padilla, Tamaulipas, México. I was particularly[513]impressed by the lack of whitish dots on the dark carapace; the following notes were taken from the freshly-killed specimen: carapace a uniform dark olive, lacking white dots and having a yellowish rim widest posteriorly; tubercles on anterior edge of carapace only slightly raised, inconspicuous; top of head olive with few dots and streaks; a well-defined yellowish postocular stripe not conspicuously interrupted; sharp contrast between dark olive on side of head and pale ventral coloration; yellowish-orange ventrolaterally on head; an uninterrupted slightly-curved line connecting the anterior margins of the orbits; carapace pear-shaped; underparts whitish, lacking markings. This specimen has since been destroyed. The only other specimen I have seen from this locality is a hatchling (UMMZ 69412,Pl. 43), which has a pale brownish or tan carapace that lacks whitish dots; it resemblesemoryiin other characters. Although the absence of whitish dots is not distinctive, its combination with the uniform dark olive carapace in adult males and the fact that the Río Purificación is an isolated drainage system, suggests that soft-shelled turtles from that river system may warrant further taxonomic study.Comparisons.—From all other subspecies ofspinifer,T. s. emoryican be distinguished by having a pale rim on the carapace that is four to five times wider posteriorly than it is laterally. This character, unique foremoryi, combined with patterns on the snout, side of head and carapace that are subject to little variation, permit ready identification of the subspeciesemoryi.T. s. emoryiresemblespallidus, andguadalupensisand differs fromspinifer,hartwegiandasperin having whitish tubercles or dots on the carapace.T. s. emoryiresemblesguadalupensisbut differs frompallidus,spinifer,hartwegiandasperin lacking conical tubercles along the anterior edge of the carapace on large females. For additional differences see accounts of other subspecies.Some populations ofT. s. emoryiresembleT. muticusin the size at which sexual maturity is attained and in the development of the plastral callosities.T. s. emoryihas a wide head that resembles that ofT. ferox,T. ater,T. s. asperandT. s. guadalupensis;T. s. emoryialso resemblesT. feroxandT. aterbut differs from the other subspecies ofT. spiniferandT. muticusin having a narrower carapace.T. s. emoryiresemblesT. s. guadalupensis,T. s. pallidusandT. ater, and differs from the other subspecies ofspiniferandT. muticus, in having the carapace widest farther posteriorly than one-half way back on the carapace.T. s. emoryiresemblesT. feroxin having the shortest length of snout of the subspecies ofspinifer. The plastron is shorter than inT. ferox, longer than inT. s. asper, and about the same length as inT. muticusand the other subspecies ofT. spinifer.Remarks.—Agassiz (1857, 1:407-08) did not designate a holotype in the original description ofAspidonectes emoryi; specimens are mentioned from the lower Río Grande of Texas, near Brownsville, and a stream of the Río Brazos drainage in Williamson County, Texas. The description is applicable toT. s. emoryias herein restricted, except for the statement that the white tubercles of young specimens are "encircled by faint black lines"; that statement is presumably based on the juveniles from Williamson County.T. s. emoryidoes not occur in Williamson County, Texas. Barbour and Loveridge (1929:225) listed MCZ 1909-10 and 1627 as cotypes. Stejneger (1944:65) mentioned MCZ 1909, 1913 and USNM 7855 as cotypes; the legend for Plate 20 (op. cit.) refers to a drawing that "corresponds fairly closely with the type (MCZ 1910) collected at Brownsville, Texas, by Col. Emory."[514]The syntypic series consists of seven specimens—MCZ 1627 (two specimens) from Williamson County, Texas; MCZ 1909 (three specimens) and 1910 from Brownsville, Texas; and USNM 7855 from Brownsville, Texas. The listing of number 1913 by Stejneger is considered alapsusfor 1910 as MCZ 1913 is catalogued as aGraptemys geographica(in letter dated November 17, 1959 from Dr. Ernest E. Williams). Stejneger's reference to MCZ 1910 as the type is considered unintentional and an inadequate designation of a lectotype.In the "remarks" column of the USNM museum catalog, number 7855 is referred to as "Ag. Type." USNM 7855 is here designated as lectotype ofTrionyx spinifer emoryi. The lectotype is a young specimen (female?) that is not easily sexed by external characters; the plastron measures (in centimeters) 6.3 in length, the carapace 8.2 in length and 7.0 in width, and the head 1.4 in width. The carapace is pale brown having inconspicuous whitish dots posteriorly and a pale rim that is approximately 6.8 times wider posteriorly (4.1 mm.) than it is laterally (0.6 mm.). The slightly curved dark line connecting the anterior margins of the orbits is dimmer than the dark lines that extend forward from the eyes. The pale postocular stripes having blackish, dotted borders are interrupted; there are no other markings on the side of the head. The ventral surface is immaculate except for a few dark dots on the right side of the carapace; the ground color is pale brown or tan, but the upper layer of skin can be scraped away revealing an underlying pale lavender-cream ground color. The tubercles along the anterior edge of the carapace resemble small rounded warts.MCZ 1910 is an adult maleT. s. emoryihaving a plastron 10.7 centimeters in length. The carapace is pale brown having a relatively smooth anterior edge, inconspicuous whitish tubercles posteriorly, and a pale rim five times wider posteriorly than laterally; the pattern on the head resembles that ofemoryi.Each of three hatchlings ofT. s. emoryi, 3.4, 3.5 and 3.9 centimeters in plastral length, bears an MCZ catalogue number of 1909. The carapaces are dark tan or gray having pale rims 3.7, 5.2 and 5.2 times wider posteriorly than laterally, and white dots absent or obscure posteriorly; two specimens have small blackish dots paralleling the pale rim posteriorly. The patterns on the heads are referable toemoryi.The two juvenal syntypes (5.2 and 6.1 cm. in plastral length) from Williamson County, Texas, are both catalogued as MCZ 1627, but only one of these bears a catalogue number. The two softshells are notemoryi, and are more nearly likeT. s. guadalupensisthanT. s. pallidus. Actually, they are from an area of intergradation between those subspecies (see comments concerning intergradation under the accounts of the subspeciespallidusandguadalupensis). White spots occur on the carapaces anteriorly and posteriorly, the larger (more posterior) of which are encircled with dusky ocelli. The carapace of the small specimen (bearing no number) is brown having a few, small black specks intermixed with the white spots. The carapace of the large specimen is pale lavender and has a more obscure pattern than the other specimen.After Agassiz's description,emoryiwas accepted as a distinct species. Neill (1951:15) suggested thatemoryiwas subspecifically related toT. ferox. Crenshaw and Hopkins (1955) and Schwartz (1956), however, demonstrated thatferoxwas a distinct species;emoryihas since been considered a subspecies ofT. spinifer.[515]Two specimens having blackish dots on the carapace, indicate relationship withT. s. guadalupensis. USNM 7638, a hatchling, has large whitish dots surrounded by blackish dots confined to the posterior half of the carapace, and the locality for this specimen is merely Río Bravo (= Río Grande). CNHM 47366, a hatchling from Sierra de las Palmas (Sierra de Santa Rosa, La Palma), Coahuila, has a few, small, blackish dots, irregularly spaced, on the anterior half of the carapace, but other dots more evenly distributed on the posterior half where they are intermixed with whitish dots. The drawing of the dorsal view of a hatchlingemoryi(Agassiz, 1857:Pl. 6, Fig. 4) shows a sprinkling of blackish dots on the anterior half of the carapace. A hatchling from Eagle Pass (USNM 116578) does not have a noticeably widened pale rim posteriorly on the carapace, and is not distinguishable frompallidus. See account ofT. s. guadalupensisfor further comments on intergradation.A soft-shelled turtle that was obtained in the Sacramento River by three fishermen, near Sacramento, California, was namedAspidonectes californianaby Rivers (1889:233). A comparison (withAspidonectes spiniferandA. emoryi) of certain features of the skull was largely prepared by Baur and included in the description (op. cit.:234-35); seemingly, the most trenchant character of the skull ofcalifornianawas the enlarged alveolar surfaces of the jaws. This feature prompted Baur (1893:220) to refercalifornianato the genusPelodiscus, which also includedagassizi(skulls also having jaws with enlarged alveolar surfaces) and several Old World species. Van Denburgh (1917) discussed the origin of the specimen that formed the basis of River's description and concluded that it was brought over from China. Siebenrock (1924:192) and Mertens and Wermuth (1955:389) listedAspidonectes californianaas a synonym ofemoryi. River's description is not that ofemoryi; the enlarged alveolar surfaces of the jaws, and the dark carapace having tubercular ridges suggest a resemblance toT. ferox. The papillae on the neck are not found in any American species. Miller (1946:46, footnote 2) believed that "it obviously was introduced, apparently from China," and cited Pope (1935:61), who declared the specimen to representTrionyx sinensis.Schmidt (1924:64) first reported the occurrence ofT. s. emoryiwest of the continental divide in Arizona and suggested that it was highly probable that the species had been introduced near Phoenix in recent years. Cowles and Bogert (1936:42) mentioned a species of softshell occurring in the Boulder Dam region and presumed the species to be native to Asia and introduced by the Chinese. Linsdale and Gressitt (1937:222) determined the status of the species in the Colorado River drainage asT. s. emoryi. The discussions by Dill (1944:179-81) and Miller (1946:46) indicate thatemoryiwas introduced into the Gila River (Colorado River drainage) in western New Mexico near the turn of the century.T. s. emoryiandT. aterare the only kinds of softshells occurring in México. The colloquial name for soft-shelled turtles in México is "tortuga blanca." This name is also used in reference to the Central American river turtle,Dermatemys mawei, which occurs on the east coast of México as far north as Veracruz.Specimens examined.—Total 275, as follows:Arizona:Maricopa: CNHM 4768, KU 2214-19, 2803, 2824, 2837, 2903-07, 2909-16 (2914, 2 specimens), 2918-29, 3118-27, 3129, 3147-56, USNM 71627, Salt River, Phoenix.Pinal: UI 37713, Gila River, 6 mi. E Winkleman; UMMZ 92006-07, Gila River,1/2mi.[516]below Coolidge Dam; UMMZ 105824, San Pedro River about 1 mi. above confluence with Gila River.Nevada:Clark: AMNH 58370, Boulder City boat landing, Lake Mead; TU 15802, Virgin River, Mesquite.New Mexico:Eddy: KU 15938, Carlsbad; KU 48217-18, Black River Village.Grant: AMNH 79911, Gila River, 8 mi. NE Cliff.Texas:Brewster: CNHM 39999, Tornillo Creek near jct. with Río Grande; KU 51954-92, Lajitas; TCWC 4291, UMMZ 66471, USNM 45545, 103678, Boquillas; INHS 7975, UMMZ 114360, Hot Springs.Cameron: BCB 7564-73, CNHM 5339-40, 6810, MCZ 1909 (3), 1910, TU 11479-80, 11561-62, UMMZ 54021, 105209-13 (Brownsville Lake), USNM 7642, 7644, 7855, Brownsville; BCB 5121, 3 mi. S Harlington.El Paso: UMMZ 85085, El Paso; USNM 7641, 7701, El Paso del Norte.Hudspeth: USNM 20846, Fort Hancock on Río Grande.Kinney: CNHM 26090, Río Pinto W of Bracketville; USNM 26426-36, Fort Clark.Loving: TTC 1143, Red Bluff Lake just below dam on Pecos River.Maverick: TU 3696-97, UMMZ 116578, Eagle Pass.Presidio: TTC 628 (2), 632 (2), 3 mi. WNW Lajitas, Brewster County.Terrell: TNHC 7997, 8022-23, Chandler Ranch, 30 mi. S Sheffield, Pecos County; TNHC 8104, Dunlap Ranch, 25 mi. SE Sheffield, Pecos County; TU 14453 (7), 14462 (2), 15415, 15423, 15586, Pecos River near jct. with Independence Creek; USNM 104240, Pecos River "near" Dryden.Val Verde: TTC 113, Pecos River.Webb: TNHC 19788, 42 mi. NW Laredo; USNM 109078-79, Laredo.Zapata: UI 19332, "near" Zapata.County unknown: MCZ 1628, USNM 7635-36, 7854; USNM 7637-38, Río Bravo (= Río Grande).Chihuahua: KU 51173, 8 mi. S, 16 mi. W Ojinaga; KU 51174-86, 1 mi. NW Ojinaga; KU 51187-201, Río Conchos at mouth of Río San Pedro near Meoquí; UI 43508-09, Río Florida, La Cruz.Coahuila: CNHM 26054, Sta. Helena Canyon of Río Grande; CNHM 28846, "near" Músquis; CNHM 55657, Río Alamos, Rcho. de la Gacha; CNHM 47366, Sierra de Santa Rosa, La Palma; CNHM 47367, 55661, Cuatro Ciénegas; CNHM 55658-60, Rcho. de los Borregos near Juarez; KU 33523, La Presa Don Martín; KU 39991, 39993, 8 mi. N, 2 mi. W Piedras Negras; KU 39992, 2 mi. W Jiménez; KU 46907, 16 km. S Cuatro Ciénegas; KU 46913-16, 10 km. S Cuatro Ciénegas; KU 53752-54, Río Mesquites, 8 mi. W Nadadores; KU 53757, 8.5 mi. SW Cuatro Ciénegas; MSU 905-06, Río Sabinas, 1 mi. E Sabinas.Nuevo Leon: CNHM 1874, 2191, Rodriguez; UMMZ 69411, Río Conchos, 9 mi. N Linares.Tamaulipas: CM 3037, Nuevo Laredo. UMMZ 7614-20, 7622-25, 7628, 7630, 7632-33, Matamoros; UMMZ 69412, Río Purificación, N of Ciudad Victoria.No Data: MCZ 1629 (2), NHB 1032.Records in the literature.—Arizona:Greenlee: Gila River, Duncan (Miller, 1946:46); "near" Sheldon (Dill, 1944:180).Mohave: Pierce's Ferry just below lower end of Grand Canyon (Cowles and Bogert, 1936:42); 1.5 mi. upstream (Virgin River) from Mesquite, Clarke County, Nevada (Hardy and Lamoreaux, 1945:168); Lake Havasu on Colorado River (Dill, 1944:180).Yuma: Colorado River at Headgate Rock Dam (Dill,op. cit.:179).California:Imperial: California Lakes (Cowles and Bogert, 1936:42); Palo Verde; Colorado River at Laguna Dam (Dill, 1944:180).Nevada:Clark: observed just north of Black Canyon (Cowles and Bogert,loc. cit.); Colorado River, 6 mi. N California line (Linsdale, 1940:255).New Mexico:Chaves: Bitter Lakes Wildlife Refuge, 12 mi. NE Roswell (Bundy, 1951:314).Dona Ana: Río Grande near Mesilla Dam (Little and Keller, 1937:221).Texas:Brewster: Río Grande at Castolon (Minton, 1959:38).Val Verde: mouth of Devil's River (Brown, 1950:250).Baja California: Colorado River delta, 7 mi. E Cerro Prieto; Imperial[517]Irrigation District, Alamo Canal, 15 mi. S Internat'l Boundary and Salfatana Canal, 1 mi. N Black Butte (Linsdale and Gressitt, 1937:222).Coahuila: San Juan (Schmidt and Owens, 1944:103).Hitherto, soft-shelled turtles of the speciesTrionyx spiniferfrom the southern and southwestern United States having a pattern of white dots on the carapace have been relegated to the subspeciesemoryi, but my examination of soft-shelled turtles from Texas has indicated thatT. s. emoryias previously conceived, is a composite of three subspecies. It is necessary, therefore, to recognize two new subspecies.
Type.—Lectotype, USNM 7855; alcoholic (sex undetermined); obtained from the Río Grande near Brownsville, Texas, in the course of the Mexican Boundary Survey under the command of Colonel Wm. H. Emory.
Range.—Southwestern United States and northern México; the Río Grande drainage in Texas, New Mexico and northern México; the Río San Fernando and Río Purificación drainages in northeastern México; the Colorado River drainage in Arizona, New Mexico, and southern Nevada (see map,Fig. 19).
Diagnosis.—Juvenal pattern of white dots, not encircled with dusky or blackish ocelli, confined to posterior third of carapace; pale rim of carapace conspicuously widened, four to five times wider posteriorly than laterally; a dark triangle in front of eyes, base line connecting anterior margins of orbits; pale postocular stripe interrupted leaving conspicuous pale, usually dark-bordered, blotch just behind eye.
Description.—Plastral length of smallest hatchling, 2.5 centimeters (USNM 7632); of largest male, 13.0 centimeters (KU 2914, 3125, 3150); of largest female, 22.0 centimeters (TNHC 8023, 8104).
Carapace pale brownish or tan, lacking whitish dots on anterior half; whitish dots confined to posterior third of carapace, sometimes lacking posteriorly, especially on juveniles; small, blackish dots rarely occurring on surface of carapace, usually confined to margins when present; pale rim of carapace four to five times wider posteriorly than laterally.
Pattern on snout rarely variable, consisting of pale stripes extending forward from eyes that have only their outer borders darkened and a straight or slightly curved, dark line that connects anterior margins of orbits; few, if any, dark markings in subocular and postlabial region; pattern on side of head having few contrasting marks, often of nearly uniform coloration; postocular stripe usually interrupted; anterior segment of postocular stripe just behind eye usually dark-bordered; posterior segment usually not dark-bordered or sharply distinguished from background; pattern on dorsal parts of soft parts of body contrasting, of relatively small dark marks; dark streaks often coincident with digits.
Underparts whitish, occasionally having blackish dots or smudges on posterior part of carapace, in region of bridge, or on lateral parts of chin and throat; few dark marks often on webbing of limbs and on palms and soles.
Small, flattened or wartlike, tubercles that occasionally have sharp tips along anterior edge of carapace on adult males; tubercles flattened, scarcely elevated, never conical along anterior edge of carapace on large females; whitish, knoblike tubercles often present posteriorly in middle of carapace and in nuchal region on large females; mottled and blotched pattern sometimes contrasting on carapace of large females; whitish dots of juvenal pattern often visible through overlying blotched pattern of large females.
[511]
Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.68, and exceeding 7.0 centimeters, 5.19; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.17, and exceeding 8.5 centimeters, 1.27; mean CL/PCW, 2.18; mean HW/SL, 1.43; mean CL/PL, 1.37.
Variation.—Ten topotypes (six males, three females, one juvenile) from Brownsville, Texas (BCB 7465-73, 7564), have the following characteristics: pale rim widened posteriorly as described above; females (plastral lengths 9.8, 10.2 and 11.7 cm.) having blackish marks in pale rim, which are absent in males of corresponding size; interrupted postocular stripe with pale blotch behind eye; postocular pale blotch having blackish borders or not; dark triangular mark on snout in front of eyes; white dots present only on posterior third of carapace; carapace of females grayish, blotched pattern not contrasting; carapace of males paler, greenish-gray; undersurface immaculate except 7468 and 7472 that have blackish flecks at bridge and, on 7472, blackish marks that extend posteriorly onto ventral surface of carapace; tubercles along anterior edge of carapace flattened and rounded in adult males, more knoblike in females; largest specimen, BCB 7472, female, plastron 11.7 centimeters long.
T. s. emoryivaries more than any other subspecies ofTrionyx spinifer. A large series of males and females (KU) from the Salt River (Colorado River drainage), near Phoenix, Arizona, is characterized by many adult males having indistinct white dots on posterior half of carapace; blotching on carapace of females of contrasting lichenlike figures, but usually non-contrasting and pale brownish or tan; pale rim of carapace distinct from ground color of carapace in largest female (KU 2905, plastron 21.5 cm. in length), but having dark or dusky markings: dark interorbital stripe often lacking. AMNH 58370 (Nevada) and UMMZ 92006 (Arizona) also have the dark line connecting the anterior margins of the orbits interrupted; seemingly the dark interorbital line is most often interrupted in those softshells inhabiting the Colorado River system of Nevada and Arizona.
Other variant individuals are: TU 14453.2, 14462 and 3696 having the plastron extending slightly farther forward than the carapace, thus resemblingT. ferox; UMMZ 54021 and CNHM 39999, hatchlings, lacking distinct whitish dots on posterior half of carapace; UI 43509 and KU 39991 having stained (brown or blackish) claws; and, CNHM 6810, an adult male, lacking a spinose (sandpapery) carapace. I am unable to discern geographic variation in these or other characters.
The ground color of the carapace on some individuals from the Pecos River (TU, Terrell County, Texas) is grayish and in contrast with the pale rim (Pl. 44). UI 43509 from the Río Florida, La Cruz, Chihuahua, a female, has a dark brownish carapace with little evidence of a blotched pattern except on the pale rim of the carapace. A female and adult male from the Río Sabinas, Coahuila (MSU 905-06), also show considerable darkening on the dorsal surfaces; the pale rim is evident but not in sharp contrast to the coloration of the carapace. Notes taken on the freshly-killed Sabinas individuals are: male—carapace olive-gray; dorsal surface of soft parts of body olive-green to grayish, a bright yellow suffusion on limbs and neck; female—carapace and soft parts of body dark olive, laterally pale yellow; the plastron extends slightly farther forward than the carapace in both sexes.
Notes on coloration (judged to be the most common or "normal" type)[512]of livingemoryifrom the Río Mesquites, central Coahuila, are: Adult male (KU 53753)—pale rim butterscotch yellow; marginal line blackish; whitish dots on pale brown or tan carapace; soft parts of body olive or olive-green, slightly darker on head and paler (yellowish) on hind limbs; pale areas on side of head pale yellow, having tint of orange on neck; ventral surface white, yellow laterally on neck. Adult female (KU 53754)—carapace having contrasting blotched and mottled pattern of pale browns and tans; soft parts of body olive brown, darker brown blotching on head; dorsal surface of limbs olive-green having pale areas lemon yellow and webbing butterscotch yellow; side of neck and head, chin and throat pale lemon yellow; ventral surface white having slight red tinge to groin and soft parts posteriorly; underside of carapace near edge pale yellow.
Softshells from the Río Grande in the Big Bend region of Texas, and the Río Conchos in Chihuahua differ from other specimens ofemoryi. Fifteen adult males, KU 51187-201 (no females in sample), were taken from the mouth of the Río San Pedro at Meoquí, Chihuahua (see KU 51194,Pl. 44). They are noteworthy because of a conspicuous orange or orange-yellow on the side of the head. Another relatively consistent character is the blackish tip of snout (excepting 51199), although the degree (palest on 51190) and extent of pigmentation posteriorly on the snout is variable. Eleven males, KU 51175-85, from approximately 100 miles northeastward in the Río Conchos near Ojinaga, Chihuahua, also have the bright orange on the side of the head; the tip of the snout is not blackish, although in some it is slightly darkened. Three females, KU 51174, 51186 (from Ojinaga) and 51173 (from 8 mi. S, 16 mi. W Ojinaga), lack the orange on the side of the head; KU 51186 has a plastral length of 8.0 centimeters, whereas the other two females have the same plastral length of 16.5 centimeters (larger than any male). Nineteen adult males, KU 51965-72, 51980-90, from the Río Grande near Lajitas also have the orangish coloration on the side of the head, whereas twenty females, KU 51954-64, 51973-79, 51991-92 (three smaller than largest male) lack the coloration. The tip of the snout is not blackish on any turtle in the series from Lajitas. The smallest female, from Lajitas, having a plastral length of 6.9 centimeters, has a mottled carapace.
The orange of males is most conspicuous in the pale postocular and postlabial areas; the stripes of the snout (distally) and the color of the neck at its juncture with the immaculate ventral surface are orange-yellow. The orange coloration is confined to males (all examined were sexually mature) and is probably not of seasonal occurrence (see comments under secondary sexual variation). I have not noticed this coloration in other males of the subspeciesemoryi; however, long-preserved males might be expected to lack the orange color; the specimens mentioned above were initially preserved in alcohol. KU 51179 (plastral length 8.2 cm., from Ojinaga) is the smallest sexually mature male of the speciesspiniferthat I have seen. Another character of note is the generally greater development of the plastral callosities (resemblingmuticus) than in other subspecies ofspiniferor specimens ofemoryi; three small adult males (KU 51177, 51990, 51987, plastral length 9.3, 9.9 and 9.1 cm., respectively) have large hyoplastral and hypoplastral callosities that appear to touch medially, and callosities on the epiplastron and both preplastra.
On July 8, 1953, an adult male ofT. spiniferwas removed from a hoop-net set in the Río Purificación at Padilla, Tamaulipas, México. I was particularly[513]impressed by the lack of whitish dots on the dark carapace; the following notes were taken from the freshly-killed specimen: carapace a uniform dark olive, lacking white dots and having a yellowish rim widest posteriorly; tubercles on anterior edge of carapace only slightly raised, inconspicuous; top of head olive with few dots and streaks; a well-defined yellowish postocular stripe not conspicuously interrupted; sharp contrast between dark olive on side of head and pale ventral coloration; yellowish-orange ventrolaterally on head; an uninterrupted slightly-curved line connecting the anterior margins of the orbits; carapace pear-shaped; underparts whitish, lacking markings. This specimen has since been destroyed. The only other specimen I have seen from this locality is a hatchling (UMMZ 69412,Pl. 43), which has a pale brownish or tan carapace that lacks whitish dots; it resemblesemoryiin other characters. Although the absence of whitish dots is not distinctive, its combination with the uniform dark olive carapace in adult males and the fact that the Río Purificación is an isolated drainage system, suggests that soft-shelled turtles from that river system may warrant further taxonomic study.
Comparisons.—From all other subspecies ofspinifer,T. s. emoryican be distinguished by having a pale rim on the carapace that is four to five times wider posteriorly than it is laterally. This character, unique foremoryi, combined with patterns on the snout, side of head and carapace that are subject to little variation, permit ready identification of the subspeciesemoryi.T. s. emoryiresemblespallidus, andguadalupensisand differs fromspinifer,hartwegiandasperin having whitish tubercles or dots on the carapace.T. s. emoryiresemblesguadalupensisbut differs frompallidus,spinifer,hartwegiandasperin lacking conical tubercles along the anterior edge of the carapace on large females. For additional differences see accounts of other subspecies.
Some populations ofT. s. emoryiresembleT. muticusin the size at which sexual maturity is attained and in the development of the plastral callosities.T. s. emoryihas a wide head that resembles that ofT. ferox,T. ater,T. s. asperandT. s. guadalupensis;T. s. emoryialso resemblesT. feroxandT. aterbut differs from the other subspecies ofT. spiniferandT. muticusin having a narrower carapace.T. s. emoryiresemblesT. s. guadalupensis,T. s. pallidusandT. ater, and differs from the other subspecies ofspiniferandT. muticus, in having the carapace widest farther posteriorly than one-half way back on the carapace.T. s. emoryiresemblesT. feroxin having the shortest length of snout of the subspecies ofspinifer. The plastron is shorter than inT. ferox, longer than inT. s. asper, and about the same length as inT. muticusand the other subspecies ofT. spinifer.
Remarks.—Agassiz (1857, 1:407-08) did not designate a holotype in the original description ofAspidonectes emoryi; specimens are mentioned from the lower Río Grande of Texas, near Brownsville, and a stream of the Río Brazos drainage in Williamson County, Texas. The description is applicable toT. s. emoryias herein restricted, except for the statement that the white tubercles of young specimens are "encircled by faint black lines"; that statement is presumably based on the juveniles from Williamson County.T. s. emoryidoes not occur in Williamson County, Texas. Barbour and Loveridge (1929:225) listed MCZ 1909-10 and 1627 as cotypes. Stejneger (1944:65) mentioned MCZ 1909, 1913 and USNM 7855 as cotypes; the legend for Plate 20 (op. cit.) refers to a drawing that "corresponds fairly closely with the type (MCZ 1910) collected at Brownsville, Texas, by Col. Emory."
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The syntypic series consists of seven specimens—MCZ 1627 (two specimens) from Williamson County, Texas; MCZ 1909 (three specimens) and 1910 from Brownsville, Texas; and USNM 7855 from Brownsville, Texas. The listing of number 1913 by Stejneger is considered alapsusfor 1910 as MCZ 1913 is catalogued as aGraptemys geographica(in letter dated November 17, 1959 from Dr. Ernest E. Williams). Stejneger's reference to MCZ 1910 as the type is considered unintentional and an inadequate designation of a lectotype.
In the "remarks" column of the USNM museum catalog, number 7855 is referred to as "Ag. Type." USNM 7855 is here designated as lectotype ofTrionyx spinifer emoryi. The lectotype is a young specimen (female?) that is not easily sexed by external characters; the plastron measures (in centimeters) 6.3 in length, the carapace 8.2 in length and 7.0 in width, and the head 1.4 in width. The carapace is pale brown having inconspicuous whitish dots posteriorly and a pale rim that is approximately 6.8 times wider posteriorly (4.1 mm.) than it is laterally (0.6 mm.). The slightly curved dark line connecting the anterior margins of the orbits is dimmer than the dark lines that extend forward from the eyes. The pale postocular stripes having blackish, dotted borders are interrupted; there are no other markings on the side of the head. The ventral surface is immaculate except for a few dark dots on the right side of the carapace; the ground color is pale brown or tan, but the upper layer of skin can be scraped away revealing an underlying pale lavender-cream ground color. The tubercles along the anterior edge of the carapace resemble small rounded warts.
MCZ 1910 is an adult maleT. s. emoryihaving a plastron 10.7 centimeters in length. The carapace is pale brown having a relatively smooth anterior edge, inconspicuous whitish tubercles posteriorly, and a pale rim five times wider posteriorly than laterally; the pattern on the head resembles that ofemoryi.
Each of three hatchlings ofT. s. emoryi, 3.4, 3.5 and 3.9 centimeters in plastral length, bears an MCZ catalogue number of 1909. The carapaces are dark tan or gray having pale rims 3.7, 5.2 and 5.2 times wider posteriorly than laterally, and white dots absent or obscure posteriorly; two specimens have small blackish dots paralleling the pale rim posteriorly. The patterns on the heads are referable toemoryi.
The two juvenal syntypes (5.2 and 6.1 cm. in plastral length) from Williamson County, Texas, are both catalogued as MCZ 1627, but only one of these bears a catalogue number. The two softshells are notemoryi, and are more nearly likeT. s. guadalupensisthanT. s. pallidus. Actually, they are from an area of intergradation between those subspecies (see comments concerning intergradation under the accounts of the subspeciespallidusandguadalupensis). White spots occur on the carapaces anteriorly and posteriorly, the larger (more posterior) of which are encircled with dusky ocelli. The carapace of the small specimen (bearing no number) is brown having a few, small black specks intermixed with the white spots. The carapace of the large specimen is pale lavender and has a more obscure pattern than the other specimen.
After Agassiz's description,emoryiwas accepted as a distinct species. Neill (1951:15) suggested thatemoryiwas subspecifically related toT. ferox. Crenshaw and Hopkins (1955) and Schwartz (1956), however, demonstrated thatferoxwas a distinct species;emoryihas since been considered a subspecies ofT. spinifer.
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Two specimens having blackish dots on the carapace, indicate relationship withT. s. guadalupensis. USNM 7638, a hatchling, has large whitish dots surrounded by blackish dots confined to the posterior half of the carapace, and the locality for this specimen is merely Río Bravo (= Río Grande). CNHM 47366, a hatchling from Sierra de las Palmas (Sierra de Santa Rosa, La Palma), Coahuila, has a few, small, blackish dots, irregularly spaced, on the anterior half of the carapace, but other dots more evenly distributed on the posterior half where they are intermixed with whitish dots. The drawing of the dorsal view of a hatchlingemoryi(Agassiz, 1857:Pl. 6, Fig. 4) shows a sprinkling of blackish dots on the anterior half of the carapace. A hatchling from Eagle Pass (USNM 116578) does not have a noticeably widened pale rim posteriorly on the carapace, and is not distinguishable frompallidus. See account ofT. s. guadalupensisfor further comments on intergradation.
A soft-shelled turtle that was obtained in the Sacramento River by three fishermen, near Sacramento, California, was namedAspidonectes californianaby Rivers (1889:233). A comparison (withAspidonectes spiniferandA. emoryi) of certain features of the skull was largely prepared by Baur and included in the description (op. cit.:234-35); seemingly, the most trenchant character of the skull ofcalifornianawas the enlarged alveolar surfaces of the jaws. This feature prompted Baur (1893:220) to refercalifornianato the genusPelodiscus, which also includedagassizi(skulls also having jaws with enlarged alveolar surfaces) and several Old World species. Van Denburgh (1917) discussed the origin of the specimen that formed the basis of River's description and concluded that it was brought over from China. Siebenrock (1924:192) and Mertens and Wermuth (1955:389) listedAspidonectes californianaas a synonym ofemoryi. River's description is not that ofemoryi; the enlarged alveolar surfaces of the jaws, and the dark carapace having tubercular ridges suggest a resemblance toT. ferox. The papillae on the neck are not found in any American species. Miller (1946:46, footnote 2) believed that "it obviously was introduced, apparently from China," and cited Pope (1935:61), who declared the specimen to representTrionyx sinensis.
Schmidt (1924:64) first reported the occurrence ofT. s. emoryiwest of the continental divide in Arizona and suggested that it was highly probable that the species had been introduced near Phoenix in recent years. Cowles and Bogert (1936:42) mentioned a species of softshell occurring in the Boulder Dam region and presumed the species to be native to Asia and introduced by the Chinese. Linsdale and Gressitt (1937:222) determined the status of the species in the Colorado River drainage asT. s. emoryi. The discussions by Dill (1944:179-81) and Miller (1946:46) indicate thatemoryiwas introduced into the Gila River (Colorado River drainage) in western New Mexico near the turn of the century.
T. s. emoryiandT. aterare the only kinds of softshells occurring in México. The colloquial name for soft-shelled turtles in México is "tortuga blanca." This name is also used in reference to the Central American river turtle,Dermatemys mawei, which occurs on the east coast of México as far north as Veracruz.
Specimens examined.—Total 275, as follows:Arizona:Maricopa: CNHM 4768, KU 2214-19, 2803, 2824, 2837, 2903-07, 2909-16 (2914, 2 specimens), 2918-29, 3118-27, 3129, 3147-56, USNM 71627, Salt River, Phoenix.Pinal: UI 37713, Gila River, 6 mi. E Winkleman; UMMZ 92006-07, Gila River,1/2mi.[516]below Coolidge Dam; UMMZ 105824, San Pedro River about 1 mi. above confluence with Gila River.
Nevada:Clark: AMNH 58370, Boulder City boat landing, Lake Mead; TU 15802, Virgin River, Mesquite.
New Mexico:Eddy: KU 15938, Carlsbad; KU 48217-18, Black River Village.Grant: AMNH 79911, Gila River, 8 mi. NE Cliff.
Texas:Brewster: CNHM 39999, Tornillo Creek near jct. with Río Grande; KU 51954-92, Lajitas; TCWC 4291, UMMZ 66471, USNM 45545, 103678, Boquillas; INHS 7975, UMMZ 114360, Hot Springs.Cameron: BCB 7564-73, CNHM 5339-40, 6810, MCZ 1909 (3), 1910, TU 11479-80, 11561-62, UMMZ 54021, 105209-13 (Brownsville Lake), USNM 7642, 7644, 7855, Brownsville; BCB 5121, 3 mi. S Harlington.El Paso: UMMZ 85085, El Paso; USNM 7641, 7701, El Paso del Norte.Hudspeth: USNM 20846, Fort Hancock on Río Grande.Kinney: CNHM 26090, Río Pinto W of Bracketville; USNM 26426-36, Fort Clark.Loving: TTC 1143, Red Bluff Lake just below dam on Pecos River.Maverick: TU 3696-97, UMMZ 116578, Eagle Pass.Presidio: TTC 628 (2), 632 (2), 3 mi. WNW Lajitas, Brewster County.Terrell: TNHC 7997, 8022-23, Chandler Ranch, 30 mi. S Sheffield, Pecos County; TNHC 8104, Dunlap Ranch, 25 mi. SE Sheffield, Pecos County; TU 14453 (7), 14462 (2), 15415, 15423, 15586, Pecos River near jct. with Independence Creek; USNM 104240, Pecos River "near" Dryden.Val Verde: TTC 113, Pecos River.Webb: TNHC 19788, 42 mi. NW Laredo; USNM 109078-79, Laredo.Zapata: UI 19332, "near" Zapata.County unknown: MCZ 1628, USNM 7635-36, 7854; USNM 7637-38, Río Bravo (= Río Grande).
Chihuahua: KU 51173, 8 mi. S, 16 mi. W Ojinaga; KU 51174-86, 1 mi. NW Ojinaga; KU 51187-201, Río Conchos at mouth of Río San Pedro near Meoquí; UI 43508-09, Río Florida, La Cruz.
Coahuila: CNHM 26054, Sta. Helena Canyon of Río Grande; CNHM 28846, "near" Músquis; CNHM 55657, Río Alamos, Rcho. de la Gacha; CNHM 47366, Sierra de Santa Rosa, La Palma; CNHM 47367, 55661, Cuatro Ciénegas; CNHM 55658-60, Rcho. de los Borregos near Juarez; KU 33523, La Presa Don Martín; KU 39991, 39993, 8 mi. N, 2 mi. W Piedras Negras; KU 39992, 2 mi. W Jiménez; KU 46907, 16 km. S Cuatro Ciénegas; KU 46913-16, 10 km. S Cuatro Ciénegas; KU 53752-54, Río Mesquites, 8 mi. W Nadadores; KU 53757, 8.5 mi. SW Cuatro Ciénegas; MSU 905-06, Río Sabinas, 1 mi. E Sabinas.
Nuevo Leon: CNHM 1874, 2191, Rodriguez; UMMZ 69411, Río Conchos, 9 mi. N Linares.
Tamaulipas: CM 3037, Nuevo Laredo. UMMZ 7614-20, 7622-25, 7628, 7630, 7632-33, Matamoros; UMMZ 69412, Río Purificación, N of Ciudad Victoria.
No Data: MCZ 1629 (2), NHB 1032.
Records in the literature.—Arizona:Greenlee: Gila River, Duncan (Miller, 1946:46); "near" Sheldon (Dill, 1944:180).Mohave: Pierce's Ferry just below lower end of Grand Canyon (Cowles and Bogert, 1936:42); 1.5 mi. upstream (Virgin River) from Mesquite, Clarke County, Nevada (Hardy and Lamoreaux, 1945:168); Lake Havasu on Colorado River (Dill, 1944:180).Yuma: Colorado River at Headgate Rock Dam (Dill,op. cit.:179).
California:Imperial: California Lakes (Cowles and Bogert, 1936:42); Palo Verde; Colorado River at Laguna Dam (Dill, 1944:180).
Nevada:Clark: observed just north of Black Canyon (Cowles and Bogert,loc. cit.); Colorado River, 6 mi. N California line (Linsdale, 1940:255).
New Mexico:Chaves: Bitter Lakes Wildlife Refuge, 12 mi. NE Roswell (Bundy, 1951:314).Dona Ana: Río Grande near Mesilla Dam (Little and Keller, 1937:221).
Texas:Brewster: Río Grande at Castolon (Minton, 1959:38).Val Verde: mouth of Devil's River (Brown, 1950:250).
Baja California: Colorado River delta, 7 mi. E Cerro Prieto; Imperial[517]Irrigation District, Alamo Canal, 15 mi. S Internat'l Boundary and Salfatana Canal, 1 mi. N Black Butte (Linsdale and Gressitt, 1937:222).
Coahuila: San Juan (Schmidt and Owens, 1944:103).
Hitherto, soft-shelled turtles of the speciesTrionyx spiniferfrom the southern and southwestern United States having a pattern of white dots on the carapace have been relegated to the subspeciesemoryi, but my examination of soft-shelled turtles from Texas has indicated thatT. s. emoryias previously conceived, is a composite of three subspecies. It is necessary, therefore, to recognize two new subspecies.
Trionyx spinifer guadalupensisnew subspeciesGuadalupe Spiny Softshell
Plates41and42
Holotype.—UMMZ 89926, alcoholic adult male; obtained 15 miles northeast Tilden, McMullen County, Texas (Pl. 41, bottom, left).Paratypes.—Forty-two specimens: ANSP 16717 (hatchling), no data; USNM 78515-16 (hatchlings), Colleto Creek, Victoria County, Texas; TU 10143-45, 10148, 10150-59, 10161-65 (adult males), TU 10176, 10833 (immature males), TU 10147, 10149, 10155 (immature females), TU 10160 (adult female), Guadalupe River, 9 miles southeast Kerrville, Kerr County, Texas; UMMZ 89915-21, 89924-27 (adult males), UMMZ 89922-23 (immature females), same locality as holotype; UMMZ 92752 (immature female), San Antonio River, 3 miles west-northwest Goliad, Victoria County, Texas.Description of holotype.—Carapace nearly circular, widest at level of posterior border of hypoplastra; margin entire; dorsal surface "sandpapery" to touch; pale rim separated from ground color of carapace by well-defined, blackish line that is wavy and narrowly interrupted posteriorly and anteriorly; pale rim approximately 1.8 times wider posteriorly (5.4 mm.) than laterally (3.0 mm.); pale rim increasingly narrower anteriorly, absent in nuchal region; tubercles in nuchal region low, scarcely elevated, lacking sharp tips; ground color of carapace olive having pattern of whitish spots and small tubercles; most whitish tubercles inconspicuous pinpoints; other small tubercles in center of whitish spots, mostly approximately 2 millimeters in diameter; largest white spot 3.4 millimeters in diameter; most white spots surrounded by blackish ocelli or parts thereof; whitish spots distributed over entire surface of carapace; certain features of bony carapace evident through overlying skin; carapace highest in region of second and third neurals, forming obtuse, gently sloping, vertebral, keel; undersurface of carapace butterscotch yellow, lacking markings; maximum length, 16.5 centimeters; greatest width, 13.5 centimeters.Plastral surface butterscotch yellow, lacking markings, extending slightly farther forward than carapace; anterior and posterior lobes rounded; anterior lobe slightly truncate; certain features of bony elements of plastron visible through overlying skin; maximum length of plastron, 12.0 centimeters.Head, extended to posterior level of eyes, terminating in flexible snout; septal ridges projecting into each rounded nostril; jaws closed, each covered by fleshy lips except anteriorly where horny portions exposed; dark triangular mark in front of eyes, base line connecting anterior margins of orbits forming series of[518]dots; pale stripes extending forward from eyes having faint inner, blackish borders; eyelids partly open having blackish dots; pale subocular blotch on right side of head having border of black dots.Forefeet and hind feet well-webbed having five digits each; each limb having nails on first three digits; each forelimb with four antebrachial scales, three of these having free edge; each hind limb with two horny scales, one smooth on posterodorsal surface and other with free edge on posteroventral surface; pattern toward insertion of forelimbs indistinct.Tail terminating in flexible point; penis exposed; cloacal opening extending beyond posterior edge of carapace; tail olive above bordered by blackish marks; few black dots laterally on left side.Undersurface of soft parts of body buff, lacking markings; few dark marks posteriorly on webbing of limbs, encroaching on soles and palms.Range.—Southcentral Texas in the drainage systems of the Nueces and Guadalupe-San Antonio rivers; the Colorado River drainage in Texas is inhabited by a population that more closely resemblesguadalupensisthanpallidus. See comments under subsection entitled "Remarks" andFig. 19.Diagnosis.—Juvenal pattern of white dots that are conspicuous on anterior half of carapace, and usually as large as those on posterior half; white dots, sometimes 3 millimeters in diameter, encircled with blackish ocelli in adult males.Description.—Plastral length of smallest hatchling, 3.3 centimeters (ANSP 16717); of largest male, 13.5 centimeters (TU 10162); of largest female, 22.0 centimeters (TU 10160).Hatchlings having white dots on anterior half of carapace; white dots anteriorly nearly as large as those posteriorly, encircled with blackish ocelli, and conspicuous on dark background (ANSP 16717,Pl. 41; USNM 78515-16; Stebbins, 1954:181, Pl. 26B), or smaller than those posteriorly, not encircled with dusky ocelli, and inconspicuous on pale background (TNHC 1446); pale rim of carapace less than four times as wide posteriorly as laterally.Adult males resembling holotype; size of white tubercles on carapace variable; most, if not all, tubercles surrounded by narrow blackish ocelli, or parts thereof; largest white tubercles or dots in most specimens exceeding one millimeter and in some specimens three millimeters in diameter (TU 10163); white dots often slightly elongate (UMMZ 89917, 89920, 89926; TU 10152, 10145); juvenal pattern of white dots seemingly more contrasting inguadalupensis, owing to dark ground color of carapace, than inpallidusoremoryithat have pale brown or tan carapaces; small tubercles along anterior edge of carapace rounded, obtuse, wartlike, never conical; sharp tips often lacking (TU 10153).Large females often having whitish spots on anterior half of carapace (TU 10160,Pl. 42, upper, right; 10142); carapace dark having ill-defined mottled and blotched pattern; tubercles along anterior edge of carapace low, rounded, rarely equilateral, never conical; small blackish dots rarely on surface of carapace (UMMZ 89923).Pattern on side of head and snout of little diagnostic value; postocular stripe usually interrupted, but configuration variable, consisting of pale anterior, dark-bordered segment (just behind eye); posterior segment of postocular[519]stripe usually less well-defined and generally blending with adjacent ground color; pale postocular stripe sometimes uninterrupted and dark-bordered throughout its length (TU 10157, 10159, 10176); pattern on dorsal surface of snout variable; pattern usually consisting of uninterrupted dark line (slightly curved anteriorly) connecting anterior margins of orbits (TU 10161, 10164, 10159, 10143), or dark line interrupted (TU 10153, 10154, 10176), absent (TU 10163), or present in addition to dark inner borders of pale stripes that extend anteriorly from eyes (TU 10149, 10162); small, often fine, dark markings, on dorsal surface of limbs, especially forelimbs; ventral surface of plastron and soft parts of body usually whitish, lacking markings; small blackish spots occasionally in region of bridge (TU 10149); dark marks occurring on webbing of limbs and often encroaching on soles and palms.Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.83, and exceeding 7.0 centimeters, 5.18; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastron lengths 8.5 centimeters or less, 1.14, and exceeding 8.5 centimeters, 1.22; mean CL/PCW, 2.11; mean HW/SL, 1.38 (including subspeciespallidus); mean CL/PL, 1.37.Variation.—Two hatchlings (ANSP 13447, Bexar County; TNHC 1446, McMullen County) more closely resemblepallidusthanguadalupensis.Some individuals from the Colorado River drainage have features suggesting those that are characteristic ofpallidus. Large females have obtuse, knoblike somewhat triangular-shaped tubercles along the anterior edge of the carapace, which are never conelike (TU 14439-40, 10187, 16036.1; BCB 6010). The tubercles along the anterior edge of the carapace are more elevated than in turtles from drainage systems west of the Colorado. Whitish spots are usually absent anteriorly on the carapace, but may be evident through the mottled pattern of large females (BCB 6010, plastral length, 19.7 cm.). The pale postocular stripe is usually interrupted, whereas the dark line connecting the anterior margins of the orbits is usually not interrupted; the two characters last mentioned show alliance withguadalupensis.The carapace of hatchlings from the Colorado River is pale having whitish dots, smaller anteriorly than posteriorly, which may be encircled with dusky ocelli (TNHC 20257) or not (ANSP 11889, BCB 5055, SM 3282). Many hatchlings are not distinguishable frompallidus(TCWC 7262, TNHC 4975, SM 4924, 6106). I have not seen hatchlings from the Colorado River that resemble ANSP 16717.The pattern on the carapace of adult males from the Colorado River drainage resembles that ofguadalupensis(Pl. 41, bottom, right) but the whitish dots are usually smaller and may not be encircled with blackish ocelli (BCB 4066, TU 14485). An adult male (TU 14476) from the South Fork of the Llano River has whitish dots three millimeters in diameter and encircled with blackish ocelli (guadalupensis), whereas another adult male (USNM 83690) from a tributary of the Colorado, the South Concho River, resemblespallidus.Eight specimens from the San Saba River (TU 14419 [6 specimens], 14439-40), that range in plastral length from 6.8 to 17.0 centimeters are impressive because of the dark brownish coloration on the carapace. The smallest individual, which is also the only male in the series, is paler. The mottled and[520]blotched pattern on the females is therefore not contrasting; the largest females have elevated whitish prominences in the center of the carapace posteriorly. An immature male (UMMZ 70348) from the South Concho River also has a dark brown carapace, and lacks white dots. The dark coloration of the carapace of these specimens recalls the TU series ofT. s. emoryifrom the Pecos River, Terrell County, Texas.Color notes taken from a freshly-killed adult female from the Llano River, two miles west Llano (TU 16036.1,Pl. 42), are: pattern on carapace of dark olive or blackish marks that form an irregular reticulum or marbling on a paler background that varies from brownish to buff and has an orange or reddish tinge in some areas; small whitish spots posteriorly; pale rim yellowish, evident only at sides of carapace; dorsal surface of soft parts of body olive-green, becoming paler with yellowish tinge toward insertions of limbs and neck; no contrasting pattern on limbs or neck and head; yellowish on sides of body; ventral surface whitish lacking dark marks, yellowish at region of bridge, axillary region and on neck; chin olive-yellow.Comparisons.—T. s. guadalupensiscan be distinguished from all other subspecies ofT. spiniferin having: (1) large white dots, sometimes three millimeters in diameter, on a dark background usually surrounded with blackish ocelli and conspicuous on the anterior half of the carapace (some as large as those on posterior half) in adult males, and (2) whitish dots on the anterior half of the carapace, in hatchlings, that are often encircled with dark ocelli.T. s. guadalupensisresemblespallidusandemoryiin having white tubercles or dots on the carapace and therein differs fromspinifer,hartwegiandasper.T. s. guadalupensisresemblespallidusbut differs fromemoryiin having a pale rim that is less than four times wider posteriorly than laterally.T. s. guadalupensisresemblesemoryibut differs frompallidus,spinifer,hartwegiandasperin having along the anterior edge of the carapace tubercles that are flattened or wartlike prominences often lacking sharp tips in adult males; these tubercles are never conical in large females.T. s. guadalupensishas a wide head, a feature shared with the subspeciesasperandemoryi, but differs fromemoryiin having a wider carapace.T. s. guadalupensisresemblesemoryiandpallidusbut differs from the other subspecies in having the carapace widest farther posterior than one-half the length of the carapace. The length of snout inpallidusandguadalupensisis shorter than inspiniferandhartwegibut is longer than inemoryi.T. s. guadalupensisdiffers fromasperbut resembles the other subspecies in having a relatively long plastron.Remarks.—Some individuals ofguadalupensishave characteristics that are applicable toemoryi. TNHC 12352 (Llano River) a hatchling, has conspicuous white dots confined to the posterior third of the carapace; the pale rim, however, is not widened posteriorly. TU 10156 (Guadalupe River) has a conspicuously widened pale rim on the carapace that is approximately 3.4 times wider posteriorly (8.5 mm.) than laterally (2.5 mm.).T. s. guadalupensismore closely resemblespallidusthanemoryi. Turtles living in rivers that drain into the Gulf of Mexico east of the Guadalupe-San Antonio river system successively show increasing resemblance topallidusfrom west to east.The expression of intergradation betweenguadalupensisandpallidusis of a clinal nature that involves parallel changes in the pattern on the snout,[521]side of head, limbs (to a lesser degree), tuberculation along the anterior edge of the carapace, size of whitish tubercles or dots, and the distinctness of the blackish ocelli that surround the whitish dots on the carapace. These characters form a well-marked gradation or cline that extends over a considerable area. There is, however, no continuous environmental gradient because the populations are relatively isolated by occupying adjacent drainage systems. The sharpest break in the gradation of characters mentioned above occurs between the Colorado River and Brazos River drainages. The population of softshells in the Colorado River drainage is actually an intergradient one, but more closely resemblesguadalupensis, whereas the population in the Brazos River drainage more closely resemblespallidus. For convenience the turtles inhabiting the Colorado River drainage are referred toguadalupensisand those in the Brazos River drainage topallidus. Some individuals from farther west than the Colorado River drainage will resemblepallidus, and a few individuals from father east than the Brazos River drainage will resembleguadalupensis.The gradation of some of the characters mentioned above terminates in the subspeciesemoryi. It, however, has characters not found inpallidusorguadalupensis, and is more distinct from either of those subspecies than either is from each other; the difference in characters as well as the break in the gradient of characters betweenguadalupensisin the Nueces River drainage andemoryiin the Río Grande drainage is greater than that betweenguadalupensisin the Colorado andpallidusin the Brazos River drainages.I have refrained from designating individuals between these three subspecies (emoryi,guadalupensisandpallidus) as "intergrades" on the distribution maps, and only mention (in text) those individuals whose characters show a decided tendency toward the adjacent subspecies. For further comments on intergradation see the account ofT. s. pallidus.Specimens examined.—Total 97, as follows:Texas:Bandera: KU 50834, Hondo Creek, 4 mi. W Bandera; TNHC 797-98, 7 mi. SW Medina.Bexar: ANSP 13447, Helotes; MCZ 4587; USNM 10789, 71009, San Antonio.Borden: BCB 4066, 7 mi. N Vincent.Brown: TNHC 7262, 1 mi. E Brownwood.Comal: USNM 7700, New Braunfels.Dawson: TNHC 21594-95, 10 mi. E Lamesa.Frio: USNM 7747, Río Seco.Gillespie: TU 10185, 10187, 10205, Beaver Creek, "near" Doss.Hays: AMNH 29950-52, San Marcos.Kerr: SM 2553, headwaters Turtle Creek; TU 10142-45, 10147-65, 10176, 10833, Guadalupe River, 9 mi. SE Kerrville.Kimble: BCB 5052-55, 6010, 3 mi. SE Telegraph; TU 14476, South Fork Llano River, 1.5 mi. SE Telegraph; TU 14485, Llano River, 10 mi. W Junction.Lavaca: SM 2554-55, 2559, 3 mi. NNE Hope.Llano: TNHC 12352, TU 16036 (2), Llano River, 2 mi. W Llano.McMullen: TNHC 1446, 10 mi. W Simmons, Live Oak County; UMMZ 89915-27, 15 mi. NE Tilden.Matagorda: ANSP 11889, Matagorda.San Saba: SM 6106; TU 14419 (6), 14439-40, San Saba River, 11 mi. NNW San Saba.Tom Green: SM 3282, UMMZ 70348, USNM 83690, South Concho River at Christoval.Travis: SM 659-60, 8.5 mi. from mouth of Onion Creek in Colorado River near Austin; SM 4924, Onion Creek; TNHC 4975, Upper Bull Creek; TNHC 20257, Marshall Ford Dam.Victoria: CM 3118, Black Bayou; UMMZ 92752, San Antonio River, 3 mi. WSW Goliad; USNM 78515-17, Colleto Creek, Guadalupe River.County unknown: ANSP 16717; TNHC 1404.Records in the literature.—Texas:Bandera: 24 mi. WNW Medina (Brown, 1950:250).Burnet: Colorado River (Strecker, 1909:8).Gillespie: 20 mi. N Harper (Brown,loc. cit.).Kendall: Cibolo Creek at Boerne (Strecker, 1926:8).Kerr: Guadalupe River, 3 mi. above Kerrville (TCWC 474, listed in card file).Mason: 12 mi. NE Mason (TCWC 3303, listed in card file).[522]Matagorda: Bay City (Brown,loc. cit.).Real: (Stejneger, 1944:66).Wilson: Cibolo River, 30 or 40 mi. N Sutherland Springs (Strecker, 1935:23).
Holotype.—UMMZ 89926, alcoholic adult male; obtained 15 miles northeast Tilden, McMullen County, Texas (Pl. 41, bottom, left).
Paratypes.—Forty-two specimens: ANSP 16717 (hatchling), no data; USNM 78515-16 (hatchlings), Colleto Creek, Victoria County, Texas; TU 10143-45, 10148, 10150-59, 10161-65 (adult males), TU 10176, 10833 (immature males), TU 10147, 10149, 10155 (immature females), TU 10160 (adult female), Guadalupe River, 9 miles southeast Kerrville, Kerr County, Texas; UMMZ 89915-21, 89924-27 (adult males), UMMZ 89922-23 (immature females), same locality as holotype; UMMZ 92752 (immature female), San Antonio River, 3 miles west-northwest Goliad, Victoria County, Texas.
Description of holotype.—Carapace nearly circular, widest at level of posterior border of hypoplastra; margin entire; dorsal surface "sandpapery" to touch; pale rim separated from ground color of carapace by well-defined, blackish line that is wavy and narrowly interrupted posteriorly and anteriorly; pale rim approximately 1.8 times wider posteriorly (5.4 mm.) than laterally (3.0 mm.); pale rim increasingly narrower anteriorly, absent in nuchal region; tubercles in nuchal region low, scarcely elevated, lacking sharp tips; ground color of carapace olive having pattern of whitish spots and small tubercles; most whitish tubercles inconspicuous pinpoints; other small tubercles in center of whitish spots, mostly approximately 2 millimeters in diameter; largest white spot 3.4 millimeters in diameter; most white spots surrounded by blackish ocelli or parts thereof; whitish spots distributed over entire surface of carapace; certain features of bony carapace evident through overlying skin; carapace highest in region of second and third neurals, forming obtuse, gently sloping, vertebral, keel; undersurface of carapace butterscotch yellow, lacking markings; maximum length, 16.5 centimeters; greatest width, 13.5 centimeters.
Plastral surface butterscotch yellow, lacking markings, extending slightly farther forward than carapace; anterior and posterior lobes rounded; anterior lobe slightly truncate; certain features of bony elements of plastron visible through overlying skin; maximum length of plastron, 12.0 centimeters.
Head, extended to posterior level of eyes, terminating in flexible snout; septal ridges projecting into each rounded nostril; jaws closed, each covered by fleshy lips except anteriorly where horny portions exposed; dark triangular mark in front of eyes, base line connecting anterior margins of orbits forming series of[518]dots; pale stripes extending forward from eyes having faint inner, blackish borders; eyelids partly open having blackish dots; pale subocular blotch on right side of head having border of black dots.
Forefeet and hind feet well-webbed having five digits each; each limb having nails on first three digits; each forelimb with four antebrachial scales, three of these having free edge; each hind limb with two horny scales, one smooth on posterodorsal surface and other with free edge on posteroventral surface; pattern toward insertion of forelimbs indistinct.
Tail terminating in flexible point; penis exposed; cloacal opening extending beyond posterior edge of carapace; tail olive above bordered by blackish marks; few black dots laterally on left side.
Undersurface of soft parts of body buff, lacking markings; few dark marks posteriorly on webbing of limbs, encroaching on soles and palms.
Range.—Southcentral Texas in the drainage systems of the Nueces and Guadalupe-San Antonio rivers; the Colorado River drainage in Texas is inhabited by a population that more closely resemblesguadalupensisthanpallidus. See comments under subsection entitled "Remarks" andFig. 19.
Diagnosis.—Juvenal pattern of white dots that are conspicuous on anterior half of carapace, and usually as large as those on posterior half; white dots, sometimes 3 millimeters in diameter, encircled with blackish ocelli in adult males.
Description.—Plastral length of smallest hatchling, 3.3 centimeters (ANSP 16717); of largest male, 13.5 centimeters (TU 10162); of largest female, 22.0 centimeters (TU 10160).
Hatchlings having white dots on anterior half of carapace; white dots anteriorly nearly as large as those posteriorly, encircled with blackish ocelli, and conspicuous on dark background (ANSP 16717,Pl. 41; USNM 78515-16; Stebbins, 1954:181, Pl. 26B), or smaller than those posteriorly, not encircled with dusky ocelli, and inconspicuous on pale background (TNHC 1446); pale rim of carapace less than four times as wide posteriorly as laterally.
Adult males resembling holotype; size of white tubercles on carapace variable; most, if not all, tubercles surrounded by narrow blackish ocelli, or parts thereof; largest white tubercles or dots in most specimens exceeding one millimeter and in some specimens three millimeters in diameter (TU 10163); white dots often slightly elongate (UMMZ 89917, 89920, 89926; TU 10152, 10145); juvenal pattern of white dots seemingly more contrasting inguadalupensis, owing to dark ground color of carapace, than inpallidusoremoryithat have pale brown or tan carapaces; small tubercles along anterior edge of carapace rounded, obtuse, wartlike, never conical; sharp tips often lacking (TU 10153).
Large females often having whitish spots on anterior half of carapace (TU 10160,Pl. 42, upper, right; 10142); carapace dark having ill-defined mottled and blotched pattern; tubercles along anterior edge of carapace low, rounded, rarely equilateral, never conical; small blackish dots rarely on surface of carapace (UMMZ 89923).
Pattern on side of head and snout of little diagnostic value; postocular stripe usually interrupted, but configuration variable, consisting of pale anterior, dark-bordered segment (just behind eye); posterior segment of postocular[519]stripe usually less well-defined and generally blending with adjacent ground color; pale postocular stripe sometimes uninterrupted and dark-bordered throughout its length (TU 10157, 10159, 10176); pattern on dorsal surface of snout variable; pattern usually consisting of uninterrupted dark line (slightly curved anteriorly) connecting anterior margins of orbits (TU 10161, 10164, 10159, 10143), or dark line interrupted (TU 10153, 10154, 10176), absent (TU 10163), or present in addition to dark inner borders of pale stripes that extend anteriorly from eyes (TU 10149, 10162); small, often fine, dark markings, on dorsal surface of limbs, especially forelimbs; ventral surface of plastron and soft parts of body usually whitish, lacking markings; small blackish spots occasionally in region of bridge (TU 10149); dark marks occurring on webbing of limbs and often encroaching on soles and palms.
Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.83, and exceeding 7.0 centimeters, 5.18; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastron lengths 8.5 centimeters or less, 1.14, and exceeding 8.5 centimeters, 1.22; mean CL/PCW, 2.11; mean HW/SL, 1.38 (including subspeciespallidus); mean CL/PL, 1.37.
Variation.—Two hatchlings (ANSP 13447, Bexar County; TNHC 1446, McMullen County) more closely resemblepallidusthanguadalupensis.
Some individuals from the Colorado River drainage have features suggesting those that are characteristic ofpallidus. Large females have obtuse, knoblike somewhat triangular-shaped tubercles along the anterior edge of the carapace, which are never conelike (TU 14439-40, 10187, 16036.1; BCB 6010). The tubercles along the anterior edge of the carapace are more elevated than in turtles from drainage systems west of the Colorado. Whitish spots are usually absent anteriorly on the carapace, but may be evident through the mottled pattern of large females (BCB 6010, plastral length, 19.7 cm.). The pale postocular stripe is usually interrupted, whereas the dark line connecting the anterior margins of the orbits is usually not interrupted; the two characters last mentioned show alliance withguadalupensis.
The carapace of hatchlings from the Colorado River is pale having whitish dots, smaller anteriorly than posteriorly, which may be encircled with dusky ocelli (TNHC 20257) or not (ANSP 11889, BCB 5055, SM 3282). Many hatchlings are not distinguishable frompallidus(TCWC 7262, TNHC 4975, SM 4924, 6106). I have not seen hatchlings from the Colorado River that resemble ANSP 16717.
The pattern on the carapace of adult males from the Colorado River drainage resembles that ofguadalupensis(Pl. 41, bottom, right) but the whitish dots are usually smaller and may not be encircled with blackish ocelli (BCB 4066, TU 14485). An adult male (TU 14476) from the South Fork of the Llano River has whitish dots three millimeters in diameter and encircled with blackish ocelli (guadalupensis), whereas another adult male (USNM 83690) from a tributary of the Colorado, the South Concho River, resemblespallidus.
Eight specimens from the San Saba River (TU 14419 [6 specimens], 14439-40), that range in plastral length from 6.8 to 17.0 centimeters are impressive because of the dark brownish coloration on the carapace. The smallest individual, which is also the only male in the series, is paler. The mottled and[520]blotched pattern on the females is therefore not contrasting; the largest females have elevated whitish prominences in the center of the carapace posteriorly. An immature male (UMMZ 70348) from the South Concho River also has a dark brown carapace, and lacks white dots. The dark coloration of the carapace of these specimens recalls the TU series ofT. s. emoryifrom the Pecos River, Terrell County, Texas.
Color notes taken from a freshly-killed adult female from the Llano River, two miles west Llano (TU 16036.1,Pl. 42), are: pattern on carapace of dark olive or blackish marks that form an irregular reticulum or marbling on a paler background that varies from brownish to buff and has an orange or reddish tinge in some areas; small whitish spots posteriorly; pale rim yellowish, evident only at sides of carapace; dorsal surface of soft parts of body olive-green, becoming paler with yellowish tinge toward insertions of limbs and neck; no contrasting pattern on limbs or neck and head; yellowish on sides of body; ventral surface whitish lacking dark marks, yellowish at region of bridge, axillary region and on neck; chin olive-yellow.
Comparisons.—T. s. guadalupensiscan be distinguished from all other subspecies ofT. spiniferin having: (1) large white dots, sometimes three millimeters in diameter, on a dark background usually surrounded with blackish ocelli and conspicuous on the anterior half of the carapace (some as large as those on posterior half) in adult males, and (2) whitish dots on the anterior half of the carapace, in hatchlings, that are often encircled with dark ocelli.T. s. guadalupensisresemblespallidusandemoryiin having white tubercles or dots on the carapace and therein differs fromspinifer,hartwegiandasper.T. s. guadalupensisresemblespallidusbut differs fromemoryiin having a pale rim that is less than four times wider posteriorly than laterally.T. s. guadalupensisresemblesemoryibut differs frompallidus,spinifer,hartwegiandasperin having along the anterior edge of the carapace tubercles that are flattened or wartlike prominences often lacking sharp tips in adult males; these tubercles are never conical in large females.
T. s. guadalupensishas a wide head, a feature shared with the subspeciesasperandemoryi, but differs fromemoryiin having a wider carapace.T. s. guadalupensisresemblesemoryiandpallidusbut differs from the other subspecies in having the carapace widest farther posterior than one-half the length of the carapace. The length of snout inpallidusandguadalupensisis shorter than inspiniferandhartwegibut is longer than inemoryi.T. s. guadalupensisdiffers fromasperbut resembles the other subspecies in having a relatively long plastron.
Remarks.—Some individuals ofguadalupensishave characteristics that are applicable toemoryi. TNHC 12352 (Llano River) a hatchling, has conspicuous white dots confined to the posterior third of the carapace; the pale rim, however, is not widened posteriorly. TU 10156 (Guadalupe River) has a conspicuously widened pale rim on the carapace that is approximately 3.4 times wider posteriorly (8.5 mm.) than laterally (2.5 mm.).
T. s. guadalupensismore closely resemblespallidusthanemoryi. Turtles living in rivers that drain into the Gulf of Mexico east of the Guadalupe-San Antonio river system successively show increasing resemblance topallidusfrom west to east.
The expression of intergradation betweenguadalupensisandpallidusis of a clinal nature that involves parallel changes in the pattern on the snout,[521]side of head, limbs (to a lesser degree), tuberculation along the anterior edge of the carapace, size of whitish tubercles or dots, and the distinctness of the blackish ocelli that surround the whitish dots on the carapace. These characters form a well-marked gradation or cline that extends over a considerable area. There is, however, no continuous environmental gradient because the populations are relatively isolated by occupying adjacent drainage systems. The sharpest break in the gradation of characters mentioned above occurs between the Colorado River and Brazos River drainages. The population of softshells in the Colorado River drainage is actually an intergradient one, but more closely resemblesguadalupensis, whereas the population in the Brazos River drainage more closely resemblespallidus. For convenience the turtles inhabiting the Colorado River drainage are referred toguadalupensisand those in the Brazos River drainage topallidus. Some individuals from farther west than the Colorado River drainage will resemblepallidus, and a few individuals from father east than the Brazos River drainage will resembleguadalupensis.
The gradation of some of the characters mentioned above terminates in the subspeciesemoryi. It, however, has characters not found inpallidusorguadalupensis, and is more distinct from either of those subspecies than either is from each other; the difference in characters as well as the break in the gradient of characters betweenguadalupensisin the Nueces River drainage andemoryiin the Río Grande drainage is greater than that betweenguadalupensisin the Colorado andpallidusin the Brazos River drainages.
I have refrained from designating individuals between these three subspecies (emoryi,guadalupensisandpallidus) as "intergrades" on the distribution maps, and only mention (in text) those individuals whose characters show a decided tendency toward the adjacent subspecies. For further comments on intergradation see the account ofT. s. pallidus.
Specimens examined.—Total 97, as follows:Texas:Bandera: KU 50834, Hondo Creek, 4 mi. W Bandera; TNHC 797-98, 7 mi. SW Medina.Bexar: ANSP 13447, Helotes; MCZ 4587; USNM 10789, 71009, San Antonio.Borden: BCB 4066, 7 mi. N Vincent.Brown: TNHC 7262, 1 mi. E Brownwood.Comal: USNM 7700, New Braunfels.Dawson: TNHC 21594-95, 10 mi. E Lamesa.Frio: USNM 7747, Río Seco.Gillespie: TU 10185, 10187, 10205, Beaver Creek, "near" Doss.Hays: AMNH 29950-52, San Marcos.Kerr: SM 2553, headwaters Turtle Creek; TU 10142-45, 10147-65, 10176, 10833, Guadalupe River, 9 mi. SE Kerrville.Kimble: BCB 5052-55, 6010, 3 mi. SE Telegraph; TU 14476, South Fork Llano River, 1.5 mi. SE Telegraph; TU 14485, Llano River, 10 mi. W Junction.Lavaca: SM 2554-55, 2559, 3 mi. NNE Hope.Llano: TNHC 12352, TU 16036 (2), Llano River, 2 mi. W Llano.McMullen: TNHC 1446, 10 mi. W Simmons, Live Oak County; UMMZ 89915-27, 15 mi. NE Tilden.Matagorda: ANSP 11889, Matagorda.San Saba: SM 6106; TU 14419 (6), 14439-40, San Saba River, 11 mi. NNW San Saba.Tom Green: SM 3282, UMMZ 70348, USNM 83690, South Concho River at Christoval.Travis: SM 659-60, 8.5 mi. from mouth of Onion Creek in Colorado River near Austin; SM 4924, Onion Creek; TNHC 4975, Upper Bull Creek; TNHC 20257, Marshall Ford Dam.Victoria: CM 3118, Black Bayou; UMMZ 92752, San Antonio River, 3 mi. WSW Goliad; USNM 78515-17, Colleto Creek, Guadalupe River.County unknown: ANSP 16717; TNHC 1404.
Records in the literature.—Texas:Bandera: 24 mi. WNW Medina (Brown, 1950:250).Burnet: Colorado River (Strecker, 1909:8).Gillespie: 20 mi. N Harper (Brown,loc. cit.).Kendall: Cibolo Creek at Boerne (Strecker, 1926:8).Kerr: Guadalupe River, 3 mi. above Kerrville (TCWC 474, listed in card file).Mason: 12 mi. NE Mason (TCWC 3303, listed in card file).[522]Matagorda: Bay City (Brown,loc. cit.).Real: (Stejneger, 1944:66).Wilson: Cibolo River, 30 or 40 mi. N Sutherland Springs (Strecker, 1935:23).
Trionyx spinifer pallidusnew subspeciesPallid Spiny Softshell
Plates39and40
Holotype.—TU 484, alcoholic adult male; obtained from Lake Caddo, Caddo Parish, Louisiana on June 27, 1947, by Fred R. Cagle and party (Pl. 39, lower, left).Paratypes.—Forty-two specimens: TU 481, 490, 678 (hatchlings), TU 381, 472, 488 (immature males), TU 475, 478, 486, 1232, 1291, 10170 (adult males), TU 399, 487 (immature females), TU 469 (adult female), Caddo Lake, Caddo Parish, Louisiana; TU 15818 (immature male), TU 15819 (adult male), Cross Lake, Caddo Parish, Louisiana; TU 1253, 13211 (adult males), TU 13266 (immature female), Sabine River, 8 miles southwest Merryville, Beauregard Parish, Louisiana; TU 13281-82 (adult males), TU 13280, 13265 (immature females), TU 13303-04, 13306 (adult females), Sabine River, 8 miles southwest Negreet, Sabine Parish, Louisiana; SM 2375 (adult male), Wallace Bayou, De Soto Parish, Louisiana; TU 1122 (adult male), Lacassine Refuge, Louisiana; UMMZ 92754 (adult male), 5 miles west Iowa, Calcasieu Parish, Louisiana; KU 40174-76, OU 27297 (adult males), OU 27290 (immature female), Lake Texoma, 2 mi. E Willis, Marshall County, Oklahoma; KU 50832 (hatchling), mouth of Caney Creek, 4 miles southwest Kingston, Marshall County, Oklahoma; CNHM 15474 (immature female), Kiowa County, Oklahoma; KU 2966-67 (immature females), KU 2934, 2947 (adult males), KU 2973 (adult female) Lewisville, Lafayette County, Arkansas.Description of holotype.—Carapace circular, widest at level of posterior edge of hyoplastra; margin entire; dorsal surface "sandpapery" to touch; pale rim separated from ground color of carapace by well-defined, slightly ragged, blackish line; pale rim approximately 2.1 times wider posteriorly (4.7 mm.) than it is laterally (2.2 mm.); pale rim increasingly narrower anteriorly, absent in nuchal region; tubercles along anterior edge of carapace triangular with sharp tips becoming flattened and inconspicuous at level of insertions of arms; ground color of carapace brownish having pattern of small whitish tubercles; most whitish tubercles inconspicuous, of pinpoint size, giving surface of carapace "sandpapery" effect; largest white tubercles posteriorly, approximately 1.2 millimeters in diameter; whitish tubercles smaller anteriorly, largest approximately 0.6 millimeters in diameter; whitish tubercles tend to form two parallel lines coincident with longitudinal sutures of neurals posteriorly in center of carapace; certain features of bony carapace evident through overlying skin; carapace highest in region of third and fourth neurals, forming obtuse, gently sloping, vertebral keel; undersurface of rear margin of carapace whitish having pinkish tinge and no markings; maximum length, 16.8 centimeters; greatest width, 14.3 centimeters.Plastral surface extending slightly farther forward than carapace, whitish having pinkish tinge and no dark markings; anterior and posterior lobes rounded, posterior lobe more acutely; certain features of bony elements of plastron visible through overlying skin; maximum length, 12.2 centimeters.Head extended, terminating in flexible snout; septal ridges projecting into each rounded nostril; tip of snout darkened; jaws open, each covered by fleshy lips except anteriorly where horny portions exposed; dark triangular mark in front of eyes, base line uninterrupted, slightly curved anteriorly, connecting anterior margins of orbits; eyelids having blackish dots, especially[523]upper, closing eyes; small blackish dots on dorsal surface of head; pale postocular stripe dark-bordered, interrupted; pale portion of stripe traversed by black line; pale subocular blotch margined by broken blackish border; side of head having contrasting blackish marks on pale background; postlabial stripe having lower blackish border on right side of head; chin with ill-defined marks, not contrasting on grayish background; well-defined, ragged black line on side of neck separating dorsal coloration from immaculate ventral coloration; small dark dots on dorsal surface of neck; dorsal surface of head and neck olive or brownish, becoming paler laterally and toward insertion of neck; maximum width of head, 2.1 centimeters.Forefeet and hind feet well-webbed each having five digits; each limb having nails on first three digits; each forelimb with four antebrachial scales, three of which have free edge; each hind limb with two horny scales, one smooth on posterodorsal surface and other with free edge on posteroventral surface; contrasting pattern of blackish marks, mostly roundish, on pale background of grayish-white.Tail terminating in flexible point; penis partly exposed; cloacal opening extending beyond posterior edge of carapace; tail having dorsal grayish band flanked by interrupted blackish lines; dark marks encroaching ventrally at tip of tail.Undersurface of soft parts of body whitish, with pinkish tinge; dark marks lacking on soles, present on webbing and palms; dark marks arranged in linear fashion coincident with digits.Range.—Southern Oklahoma, eastern Texas, extreme southwestern Arkansas, and the western half of Louisiana; Red River drainage and rivers that drain into the Gulf of Mexico east of the Brazos River drainage in Texas and west of the Atchafalaya River drainage in Louisiana. The Brazos River drainage is inhabited by a population that more closely resemblespallidusthanguadalupensis(see comments under subsection entitled "Remarks"; see map,Fig. 19).Diagnosis.—Juvenal pattern of white dots that are usually absent or inconspicuous, but sometimes distinct and small, on anterior third of carapace, and not surrounded with dark ocelli; white dots often absent on posterior half of carapace of hatchlings; white spots, rarely as large as two millimeters in diameter, not encircled with black ocelli on adult males; pale rim of carapace less than four times wider posteriorly than laterally.Description.—Plastral length of smallest hatchling, 3.3 centimeters (KU 50832); of largest male, 16.0 centimeters (SM 2375); of largest female, 30.5 centimeters (TU 13213).Surface of carapace in hatchlings uniform pale brown or tan; small white tubercles absent or inconspicuous on anterior half of carapace, but evident on posterior half of carapace, sometimes well-defined (TU 481), but usually inconspicuous (TU 678, 490); pale rim of carapace less than four times wider posteriorly than laterally.Adult males resembling description of holotype; small whitish tubercles or dots rarely two millimeters in diameter on posterior half of carapace, smaller and usually inconspicuous on anterior half of carapace (TU 13281, 486); well-defined whitish tubercles occasionally on anterior half of carapace (KU 40174); white tubercles not surrounded with black ocelli; pattern of white dots seemingly less contrasting inpallidusthan inguadalupensis, owing to pale brown or[524]tan carapace; small tubercles along anterior edge of carapace equilateral or conical having sharp tips.Large females usually having pale brown carapaces with slightly contrasting, brownish, mottled and blotched, patterns; white prominences often evident posteriorly and anteriorly in middle of carapace and in nuchal region; tubercles along anterior edge of carapace equilateral or conical in shape.Pattern on side of head and snout variable and of no diagnostic value; postocular stripe uninterrupted having dark borders (UMMZ 92754), or interrupted having pale segment behind eye (TU 13282); other variations in pattern shown on TU 10170 and 15818; pale stripes on snout having dark inner borders that join and form acute angle (TU 381), or lacking dark inner borders and having uninterrupted dark line connecting anterior margins of orbits (TU 13280); other variations in pattern on snout shown on TU 1232, 1291 and 15819; specimens representing illustrations of variation in pattern on snout (Fig. 5d, e, f) all from same locality, Lewisville, Lafayette County, Arkansas; contrasting pattern on side of head of dark marks on pale background; contrasting pattern of dark marks on dorsal surface of limbs; markings on hind limbs generally larger than those on forelimbs; small or fine markings of some specimens reducing contrast in pattern (TU 478, 488); carapace sometimes having few small blackish dots confined to margin (CNHM 15474, TU 487, 1253, 13266); ventral surface of plastron and soft parts of body whitish and usually lacking dark markings; small blackish marks often occurring on flap of carapace, in region of bridge, or on chin and throat (TU 399, 469, 475, 472, 13281).Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 4.15, and exceeding 7.0 centimeters, 5.32; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.10, and exceeding 8.5 centimeters, 1.14; mean CL/PCW, 2.12; mean HW/SL, 1.38 (including subspeciesguadalupensis); mean CL/PL, 1.36.Variation.—In 1953, I casually glanced at a hatchling softshell from the Calcasieu River drainage in the private collection of Mr. Wilfred T. Neill; the specimen was considered by Neill (1951:15) as "… an intergradient one (with thehartwegi-spiniferpopulation in the lower Mississippi drainage)." The hatchling does deviate from "typical"pallidusin having darkish flecks posteriorly on the carapace.I have seen only one adult male (USNM 94457) from the Sabine River drainage (Orange County, Texas) that shows characteristics ofguadalupensis(white dots on carapace encircled with small black ocelli); another adult male (USNM 94456) from the same locality resemblespallidus. Those two USNM specimens were mentioned by Neill (1951:13) as indicating intergradation with "… the mixedspinifera-hartwegi-asperpopulations of Louisiana."Two adult males (SM 2889,Pl. 40, bottom, left, and TCWC 471, Trinity River drainage) have blackish ocelli surrounding the white dots on the posterior part of the carapace; two large females (TU 14402,Pl. 40, bottom, right, plastral length, 17.5 cm., and TU 14417 plastral length, 21.3 cm., both from the Trinity River) have contrasting mottled and blotched patterns with white dots visible on the carapace. These turtles show alliance withguadalupensis.Some individuals from the Brazos River drainage have features suggesting[525]those that are characteristic ofguadalupensis. Hatchlings may have large white dots on the anterior half of the carapace (USNM 55601). Adult males may have dusky ocelli surrounding the white dots on the carapace (TU 14169, 14559.1, 14559.2). The whitish dots, rarely as large as two millimeters, are never so large as inguadalupensis(three mm. in diameter), and are usually smaller anteriorly than posteriorly; TU 14169 has white dots approximately the same size (1.2 mm.) on the anterior half as on the posterior half of the carapace. The tubercles on adult males are equilateral or subconical, usually having sharp tips (TU 14348, 14559.1, 14559.2); the tubercles on large females are subconical, resembling the end of a bullet, and, in both sexes the tubercles are less conical than those on specimens ofpallidusfrom farther east.Three specimens from the Brazos River drainage are particularly impressive in their alliance withguadalupensis. SM 2556, an adult male, has large white dots that are encircled with black ocelli on the posterior half of the carapace, but lacks white dots on the anterior half. TNHC 14068, a hatchling, has small black dots interspersed with the larger white dots posteriorly. CNHM 46289 has large white spots on the carapace that are surrounded with two to four black dots; scattered black dots also intermix with white spots on the surface of the carapace (less extensive anteriorly).Color notes taken from a freshly-killed adult male (KU 47121) from the Brazos River, seven miles below Whitney Dam, Bosque-Hill county line, Texas, are: Carapace pale brown or tan bordered by black line, having pale lemon yellow rim; yellowish-cream spots on carapace faintly surrounded with black stippling; dorsal surface of soft parts of body olive having black marks and patches of grayish; webbing on limbs having golden or yellowish hue, brighter distally; interorbital region brown; black-bordered, postocular stripe orange-cream; snout and side of head olive having pale areas of orange-cream; iris cream having black stripe; yellowish at juncture of dark dorsal and pale ventral coloration with orangish tinge on forelimbs and head; tail pale brown or tan, flanked by black borders that suffuse laterally into lemon-yellow; undersurface whitish, pale yellow on neck, bluish-gray on throat.Comparisons.—T. s. pallidusmost closely resemblesT. s. guadalupensis, but can be distinguished from that subspecies in having small white tubercles, rarely two millimeters in diameter, on a pale background, that are not surrounded by blackish ocelli, and are usually absent, or not conspicuous on the anterior third of the carapace in adult males; also there are usually no conspicuous white tubercles or dots on the anterior third of the carapace in hatchlings. Many adult males ofpallidusfrom the Brazos and some from the Trinity River drainages often have dusky or black ocelli surrounding the white dots posteriorly on the carapace; males from these river systems may be distinguished fromguadalupensisin having most, if not all, white dots on the anterior half of the carapace smaller than those posteriorly, and a pale brown carapace (in life, usually darker inguadalupensis).T. s. pallidus(andguadalupensis) is distinguished fromemoryiin lacking a widened pale rim posteriorly, and in having small white spots on the anterior half of the carapace.T. s. pallidusresemblesguadalupensisandemoryiin having white spots on the carapace in adult males.T. s. pallidusdiffers fromspinifer,hartwegiandasperin lacking blackish dots or ocelli that occur in the center of[526]the carapace.T. s. pallidusresemblesemoryibut differs fromguadalupensisin lacking black ocelli surrounding the white spots.T. s. pallidusresemblesspinifer,hartwegiandasperbut differs fromguadalupensisandemoryiin having tubercles along the anterior edge of the carapace that are conical having sharp tips in males, and conical in large females.T. s. pallidusresemblesspiniferandhartwegibut differs from the other subspecies in having a narrow head.T. s. pallidusdiffers fromemoryibut resembles the other subspecies in having a wider carapace.T. s. pallidusresemblesemoryiandguadalupensis, and differs from the other subspecies in having the carapace widest farther posterior than one-half the length of the carapace. The snout ofpallidusandguadalupensisis shorter than inspiniferandhartwegi, but longer than inemoryi.T. s. pallidusdiffers fromasperbut resembles the other subspecies in having a relatively long plastron.Remarks.—Intergradation of the subspeciespallidusandguadalupensisis of a clinal nature in which populations successively show a gradual resemblance toguadalupensisfrom western Louisiana and eastern Texas westward to central Texas. Because the sharpest break in this cline of characters occurs between the Colorado and Brazos River drainages, the turtles living in the Brazos River drainage and eastward are referred topallidus, whereas those in the Colorado River drainage and westward are referred toguadalupensis. For further comments on intergradation between these two subspecies, see the account ofT. s. guadalupensis.Taylor (1935:217-18) reported on some specimens ofAmyda spiniferathat were obtained by Mr. R. E. McEntyre in "… the spring and summer of 1926, chiefly about Lewisville, Lafayette County (Arkansas)." Of the catalog numbers listed by Taylor from Lewisville, 58 (KU, alcoholic) representpallidus. Three, having the same locality data, have features that are characteristic ofhartwegi. KU 2944 (one of three specimens having this catalog number) is a female having a pale, mottled and blotched carapace approximately one foot in length; there are remnants of two dark ocelli, and many widely-scattered, well-defined dark spots near the periphery of the carapace. KU 2963 (one of three specimens having this catalog number) is an adult male that has solid, blackish dots on the entire surface of the carapace. KU 2964 (one of two specimens with this catalog number) is an adult male that has ocelli approximately five millimeters in diameter on the carapace (indistinct in center of carapace).Lewisville is situated in the drainage basin of the Red River and is approximately eight miles east of the Red River and 30 miles west of the westernmost tributary of the Ouachita River drainage.T. s. pallidusoccurs in the Red River drainage;hartwegioccurs in the Ouachita River drainage. Perhaps there is intergradation betweenpallidusandhartwegiin the intervening streams. There is no data to indicate from which river or stream each specimen obtained by McEntyre came; one would presume that all specimens came from the Red River drainage. But this is not certain. Certainly the 47 specimens designated herein aspalliduscame from the Red River drainage. I suspect that KU 2944, 2963 and 2964 were obtained from tributaries of the Ouachita River drainage.T. s. pallidusintergrades with thespinifer-hartwegipopulation where the Red River joins the Mississippi River in the lower Mississippi Valley in Louisiana. The majority of 13 juvenal specimens from the Red River near Shaw, Concordia[527]Parish, Louisiana (USNM 99862-69, 99871-75), resemblepallidusin having inconspicuous white tubercles on a pale brown carapace. The white tubercles are conspicuous in USNM 99871. Some specimens have a few small dark dots confined to the margin of the carapace, as do some "variant" individuals from well within the geographic range ofpallidus. USNM 99865 is referred tohartwegibecause the carapace is covered with dark ocelli approximately one millimeter in diameter. Some specimens from farther west in the Red River drainage are referred tohartwegi. One (USNM 100420) of three from Natchitoches Parish, Louisiana (TU 5763, USNM 100420-21), having blackish dots on the carapace, is applicable tohartwegi. Of two turtles from Grant Parish, Louisiana (TU 5647, 12735), only 12735 has dark dots and ocelli (hartwegi). One specimen from Rapides Parish, Louisiana (TU 14040), having dark dots on the entire surface of the carapace, is referred tohartwegi.Most specimens from the lower Atchafalaya River drainage are referable topallidus. Eastward, intergradation occurs with thespinifer-hartwegipopulation; USNM 100089-90 from Assumption Parish, near Napoleonville, Louisiana, are referred topallidus. TU 11983, from Bayou Lafourche, Raceland, La Fourche Parish, and TU 13698.11, from Bayou Gauche in St. Charles Parish, Louisiana, are juvenal males that combine the characteristics ofpallidusandhartwegi; the carapaces are covered with blackish spots and posteriorly have distinct whitish dots. The population in the Atchafalaya River more closely resemblespallidusthan it doeshartwegiorspinifer. In former times the Atchafalaya River was presumably continuous solely with the Red River (inhabited bypallidus). Now, these two rivers and the Mississippi River are interconnected in east-central Louisiana. A large volume of water of the Mississippi drainage is conveyed to the Gulf of Mexico by the Atchafalaya, and someone has said that by approximately 1975, unless man interferes, two-thirds to three-fourths of the total volume of water of the Mississippi River will be drained by the Atchafalaya. One can expect, therefore, an increase in the influence of thehartwegi-spiniferpopulation in the Atchafalaya River drainage.Specimens examined.—Total 270, as follows:Arkansas:Lafayette: KU 2930-37, 2939-40, 2942, 2944 (two of three specimens bear this catalog number), 2945-57, 2958 (2), 2959-61, 2963 (two of three specimens bear this catalog number), 2964 (one of two specimens bears this catalog number), 2965-73, 2987-89, 3056, Lewisville.Louisiana:Acadia: USNM 100151-59, Mermentau River.Assumption: USNM 100089-90, Bayou Lafourche, "near" Napoleonville.Beauregard: TU 1231-32, 1253-55, 1291, 13211, 13266, Sabine River, 8 mi. SW Merryville.Bienville: TU 5649-50, Lake Bistineau.Caddo: TU 381, 397-99, 469-72, 474-90, 678, 10170, Caddo Lake: TU 15818-19, Cross Lake.Calcasieu: UMMZ 92754, 5 mi. W Iowa.Cameron: TU 1122, Lacassine Wildlife Refuge.Concordia: USNM 99862-64, 99866-69, 99871-75, Red River, "near" Shaw.De Soto: SM 2374-75, Wallace Bayou.Grant: TU 5647, Lake Iatt.Iberville: USNM 83985, 2 mi. E Mounds; USNM 100239-41, Grand Lake west of White Castle; USNM 100380, Plaquemine; USNM 100412, 100414-15, 100419, Spanish Lake, "near" St. Gabriel.Jefferson Davis: Calcasieu River drainage, WTN (no number, see page 524).Natchitoches: TU 5763, Bermuda; USNM 100421, "near" Natchitoches.Sabine: TU 13210, 13212-13, 13265, 13280-82, 13303-06, Sabine River, 8 mi. SW Negreet.St. Martin: USNM 100160, Bayou Chene; USNM 100650, Atchafalaya.St. Mary: USNM 100395-97, 100404, 100409-10, Berwick Bay near Morgan City.Oklahoma:Atoka: OU 8966, Rock Creek, 10 mi. E Atoka; OU 8978, McGee Creek, 7 mi. SW Daisy.Caddo: ANSP 100, Washita River, Fort Cobb.[528]Choctaw: OU 27126, Mayhew Creek, 2 mi. NW Boswell.Comanche: OU 4130, 4266, 5390, 8333, 12953, 19986, Wichita Mountains Wildlife Refuge.Jackson: OU 13012, 6 mi. E El Dorado.Kiowa: CNHM 15474.Le Flore: OU 6791, Kiamichi River, 8 mi. W Arkansas State Line.McCurtain: OU 2149-50, 2152, 2155, 17126-28, 17185, 2 mi. SW Smithville; USNM 70397, Red River.Marshall: KU 40175-76, 50830-31, 50847, OU 27290, 27297, 27562-63, TU 16076 (5), 16175 (6), 16662 (5), Lake Texoma, 2 mi. E Willis; KU 50832, mouth of Caney Creek, 4 mi. SW Kingston.Pushmataha: OU 2151, 2157; OU 11365, Buffalo Creek, 5 mi. NW Tuskahoma.Texas:Archer: TU 16174, 16668-69, Lake Diversion.Bell: SM 5667-69, Nolan Creek.Bosque: KU 47121, 7 mi. below Whitney Dam, Brazos River.Brazos: BCB 4436, 10 mi. E College Station; BCB 4437, 17 mi. S College Station; BCB 4438, 4 mi. N Bryan; KU 50833, 4 mi. W College Station; SM 2556, TCWC 472, Wickson Lake; TCWC 539, Little Brazos River; TCWC 4692, 8 mi. NE Bryan; TCWC 5121, 2 mi. S College Station; TCWC no number.Clay: TCWC 7258, 8 mi. NW Ringgold, Montague County; TU 16667.1, 3 mi. W Byers.Dallas: MCZ 3987, "near" Dallas; ANSP 13243, Dallas.Donley: ANSP 13440, S of Clarendon.Eastland: KU 3132, Cisco.Galveston: TCWC 7251, Alta Loma.Harris: UMMZ 92753, Little Cypress Creek, 1 mi. N Westfield; USNM 94335-36, "near" Houston.Harrison: USNM 95386, 16.5 mi. SE Caddo Lake.Hill: TU 14169, Richland Creek, 0.7 mi. W Mertens.Leon: CNHM 46290, 5 mi. W Marquez; TCWC 8994, 8996, 6 mi. NW Normangee.Liberty: TU 14402, 14417, Trinity River, "near" jct. with Big Creek.McLennan: BCB 4665-66, 6 mi. NNE McGregor; SM no number, 2037, 2452, 2552, 2558, 2560, 2640, 5263, 6533, Lake Waco; SM 0185, Middle Bosque River; SM 2104, 6732, Upper Bosque River; SM 5072, Bull Hide Creek; UI 2399, 1.5 mi. W China Springs; UMMZ 64063, Waco; USNM 55601.Madison: TCWC 471, 517, Twin Lakes.Montgomery: TCWC 540, 3 mi. S Conroe.Nacogdoches: TNHC 14112, Legg Creek, 5 mi. S Douglass.Orange: UMMZ 117060, 3 mi. S Orange; USNM 94456-57, Orange.Randall: TTC 576, Palo Duro Canyon, 15 mi. SE Canyon.Shackelford: TU 14547, Clear Fork Brazos River, Fort Griffin State Park.Somervell: TCWC 8995, TU 14559 (4), Brazos River, 5-6 mi. E Glen Rose.Trinity: SM 2889, Groveton.Walker: TNHC 20829, 5 mi. E New Waverly.Waller: TNHC 14068, 2.7 mi. E Brazos River on US 90.Williamson: MCZ 1627 (2); TU 14348, San Gabriel River, 6.5 mi. E Georgetown.County unknown: ANSP 13448, Wichita River; USNM 7640, Brazos River.Records in the literature.—Louisiana:Cameron: Sabine Refuge (Cagle and Chaney, 1950:386).Oklahoma:Le Flore: 6 mi. W Page.McCurtain: 14 mi. SE Broken Bow (Trowbridge, 1937:301).Texas:Bosque: Bosque River, "near" Valley Mills (Strecker, 1928:6).Harris: Addicks (Brown, 1950:250).Henderson: Cedar Creek (Strecker, 1926a:7).Jefferson: 12 mi. SW Port Arthur (Guidry, 1953:56).Liberty: Daisetta (Brown,loc. cit.); San Jacinto River (Strecker, 1915:15).McLennan: "near" Crawford (Brown,loc. cit.).Orange: 1 mi. N Bridge City (Guidry,loc. cit.).Tarrant: Trinity River, Fort Worth (Stejneger, 1944:66).Taylor: Abilene (KKA).Tyler: Colmisneil (Siebenrock, 1909:603).Walker: 6 mi. E Huntsville (TCWC 329, listed in card file).Wheeler: 5 mi. N Wheeler (Brown,loc cit.).
Holotype.—TU 484, alcoholic adult male; obtained from Lake Caddo, Caddo Parish, Louisiana on June 27, 1947, by Fred R. Cagle and party (Pl. 39, lower, left).
Paratypes.—Forty-two specimens: TU 481, 490, 678 (hatchlings), TU 381, 472, 488 (immature males), TU 475, 478, 486, 1232, 1291, 10170 (adult males), TU 399, 487 (immature females), TU 469 (adult female), Caddo Lake, Caddo Parish, Louisiana; TU 15818 (immature male), TU 15819 (adult male), Cross Lake, Caddo Parish, Louisiana; TU 1253, 13211 (adult males), TU 13266 (immature female), Sabine River, 8 miles southwest Merryville, Beauregard Parish, Louisiana; TU 13281-82 (adult males), TU 13280, 13265 (immature females), TU 13303-04, 13306 (adult females), Sabine River, 8 miles southwest Negreet, Sabine Parish, Louisiana; SM 2375 (adult male), Wallace Bayou, De Soto Parish, Louisiana; TU 1122 (adult male), Lacassine Refuge, Louisiana; UMMZ 92754 (adult male), 5 miles west Iowa, Calcasieu Parish, Louisiana; KU 40174-76, OU 27297 (adult males), OU 27290 (immature female), Lake Texoma, 2 mi. E Willis, Marshall County, Oklahoma; KU 50832 (hatchling), mouth of Caney Creek, 4 miles southwest Kingston, Marshall County, Oklahoma; CNHM 15474 (immature female), Kiowa County, Oklahoma; KU 2966-67 (immature females), KU 2934, 2947 (adult males), KU 2973 (adult female) Lewisville, Lafayette County, Arkansas.
Description of holotype.—Carapace circular, widest at level of posterior edge of hyoplastra; margin entire; dorsal surface "sandpapery" to touch; pale rim separated from ground color of carapace by well-defined, slightly ragged, blackish line; pale rim approximately 2.1 times wider posteriorly (4.7 mm.) than it is laterally (2.2 mm.); pale rim increasingly narrower anteriorly, absent in nuchal region; tubercles along anterior edge of carapace triangular with sharp tips becoming flattened and inconspicuous at level of insertions of arms; ground color of carapace brownish having pattern of small whitish tubercles; most whitish tubercles inconspicuous, of pinpoint size, giving surface of carapace "sandpapery" effect; largest white tubercles posteriorly, approximately 1.2 millimeters in diameter; whitish tubercles smaller anteriorly, largest approximately 0.6 millimeters in diameter; whitish tubercles tend to form two parallel lines coincident with longitudinal sutures of neurals posteriorly in center of carapace; certain features of bony carapace evident through overlying skin; carapace highest in region of third and fourth neurals, forming obtuse, gently sloping, vertebral keel; undersurface of rear margin of carapace whitish having pinkish tinge and no markings; maximum length, 16.8 centimeters; greatest width, 14.3 centimeters.
Plastral surface extending slightly farther forward than carapace, whitish having pinkish tinge and no dark markings; anterior and posterior lobes rounded, posterior lobe more acutely; certain features of bony elements of plastron visible through overlying skin; maximum length, 12.2 centimeters.
Head extended, terminating in flexible snout; septal ridges projecting into each rounded nostril; tip of snout darkened; jaws open, each covered by fleshy lips except anteriorly where horny portions exposed; dark triangular mark in front of eyes, base line uninterrupted, slightly curved anteriorly, connecting anterior margins of orbits; eyelids having blackish dots, especially[523]upper, closing eyes; small blackish dots on dorsal surface of head; pale postocular stripe dark-bordered, interrupted; pale portion of stripe traversed by black line; pale subocular blotch margined by broken blackish border; side of head having contrasting blackish marks on pale background; postlabial stripe having lower blackish border on right side of head; chin with ill-defined marks, not contrasting on grayish background; well-defined, ragged black line on side of neck separating dorsal coloration from immaculate ventral coloration; small dark dots on dorsal surface of neck; dorsal surface of head and neck olive or brownish, becoming paler laterally and toward insertion of neck; maximum width of head, 2.1 centimeters.
Forefeet and hind feet well-webbed each having five digits; each limb having nails on first three digits; each forelimb with four antebrachial scales, three of which have free edge; each hind limb with two horny scales, one smooth on posterodorsal surface and other with free edge on posteroventral surface; contrasting pattern of blackish marks, mostly roundish, on pale background of grayish-white.
Tail terminating in flexible point; penis partly exposed; cloacal opening extending beyond posterior edge of carapace; tail having dorsal grayish band flanked by interrupted blackish lines; dark marks encroaching ventrally at tip of tail.
Undersurface of soft parts of body whitish, with pinkish tinge; dark marks lacking on soles, present on webbing and palms; dark marks arranged in linear fashion coincident with digits.
Range.—Southern Oklahoma, eastern Texas, extreme southwestern Arkansas, and the western half of Louisiana; Red River drainage and rivers that drain into the Gulf of Mexico east of the Brazos River drainage in Texas and west of the Atchafalaya River drainage in Louisiana. The Brazos River drainage is inhabited by a population that more closely resemblespallidusthanguadalupensis(see comments under subsection entitled "Remarks"; see map,Fig. 19).
Diagnosis.—Juvenal pattern of white dots that are usually absent or inconspicuous, but sometimes distinct and small, on anterior third of carapace, and not surrounded with dark ocelli; white dots often absent on posterior half of carapace of hatchlings; white spots, rarely as large as two millimeters in diameter, not encircled with black ocelli on adult males; pale rim of carapace less than four times wider posteriorly than laterally.
Description.—Plastral length of smallest hatchling, 3.3 centimeters (KU 50832); of largest male, 16.0 centimeters (SM 2375); of largest female, 30.5 centimeters (TU 13213).
Surface of carapace in hatchlings uniform pale brown or tan; small white tubercles absent or inconspicuous on anterior half of carapace, but evident on posterior half of carapace, sometimes well-defined (TU 481), but usually inconspicuous (TU 678, 490); pale rim of carapace less than four times wider posteriorly than laterally.
Adult males resembling description of holotype; small whitish tubercles or dots rarely two millimeters in diameter on posterior half of carapace, smaller and usually inconspicuous on anterior half of carapace (TU 13281, 486); well-defined whitish tubercles occasionally on anterior half of carapace (KU 40174); white tubercles not surrounded with black ocelli; pattern of white dots seemingly less contrasting inpallidusthan inguadalupensis, owing to pale brown or[524]tan carapace; small tubercles along anterior edge of carapace equilateral or conical having sharp tips.
Large females usually having pale brown carapaces with slightly contrasting, brownish, mottled and blotched, patterns; white prominences often evident posteriorly and anteriorly in middle of carapace and in nuchal region; tubercles along anterior edge of carapace equilateral or conical in shape.
Pattern on side of head and snout variable and of no diagnostic value; postocular stripe uninterrupted having dark borders (UMMZ 92754), or interrupted having pale segment behind eye (TU 13282); other variations in pattern shown on TU 10170 and 15818; pale stripes on snout having dark inner borders that join and form acute angle (TU 381), or lacking dark inner borders and having uninterrupted dark line connecting anterior margins of orbits (TU 13280); other variations in pattern on snout shown on TU 1232, 1291 and 15819; specimens representing illustrations of variation in pattern on snout (Fig. 5d, e, f) all from same locality, Lewisville, Lafayette County, Arkansas; contrasting pattern on side of head of dark marks on pale background; contrasting pattern of dark marks on dorsal surface of limbs; markings on hind limbs generally larger than those on forelimbs; small or fine markings of some specimens reducing contrast in pattern (TU 478, 488); carapace sometimes having few small blackish dots confined to margin (CNHM 15474, TU 487, 1253, 13266); ventral surface of plastron and soft parts of body whitish and usually lacking dark markings; small blackish marks often occurring on flap of carapace, in region of bridge, or on chin and throat (TU 399, 469, 475, 472, 13281).
Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 4.15, and exceeding 7.0 centimeters, 5.32; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.10, and exceeding 8.5 centimeters, 1.14; mean CL/PCW, 2.12; mean HW/SL, 1.38 (including subspeciesguadalupensis); mean CL/PL, 1.36.
Variation.—In 1953, I casually glanced at a hatchling softshell from the Calcasieu River drainage in the private collection of Mr. Wilfred T. Neill; the specimen was considered by Neill (1951:15) as "… an intergradient one (with thehartwegi-spiniferpopulation in the lower Mississippi drainage)." The hatchling does deviate from "typical"pallidusin having darkish flecks posteriorly on the carapace.
I have seen only one adult male (USNM 94457) from the Sabine River drainage (Orange County, Texas) that shows characteristics ofguadalupensis(white dots on carapace encircled with small black ocelli); another adult male (USNM 94456) from the same locality resemblespallidus. Those two USNM specimens were mentioned by Neill (1951:13) as indicating intergradation with "… the mixedspinifera-hartwegi-asperpopulations of Louisiana."
Two adult males (SM 2889,Pl. 40, bottom, left, and TCWC 471, Trinity River drainage) have blackish ocelli surrounding the white dots on the posterior part of the carapace; two large females (TU 14402,Pl. 40, bottom, right, plastral length, 17.5 cm., and TU 14417 plastral length, 21.3 cm., both from the Trinity River) have contrasting mottled and blotched patterns with white dots visible on the carapace. These turtles show alliance withguadalupensis.
Some individuals from the Brazos River drainage have features suggesting[525]those that are characteristic ofguadalupensis. Hatchlings may have large white dots on the anterior half of the carapace (USNM 55601). Adult males may have dusky ocelli surrounding the white dots on the carapace (TU 14169, 14559.1, 14559.2). The whitish dots, rarely as large as two millimeters, are never so large as inguadalupensis(three mm. in diameter), and are usually smaller anteriorly than posteriorly; TU 14169 has white dots approximately the same size (1.2 mm.) on the anterior half as on the posterior half of the carapace. The tubercles on adult males are equilateral or subconical, usually having sharp tips (TU 14348, 14559.1, 14559.2); the tubercles on large females are subconical, resembling the end of a bullet, and, in both sexes the tubercles are less conical than those on specimens ofpallidusfrom farther east.
Three specimens from the Brazos River drainage are particularly impressive in their alliance withguadalupensis. SM 2556, an adult male, has large white dots that are encircled with black ocelli on the posterior half of the carapace, but lacks white dots on the anterior half. TNHC 14068, a hatchling, has small black dots interspersed with the larger white dots posteriorly. CNHM 46289 has large white spots on the carapace that are surrounded with two to four black dots; scattered black dots also intermix with white spots on the surface of the carapace (less extensive anteriorly).
Color notes taken from a freshly-killed adult male (KU 47121) from the Brazos River, seven miles below Whitney Dam, Bosque-Hill county line, Texas, are: Carapace pale brown or tan bordered by black line, having pale lemon yellow rim; yellowish-cream spots on carapace faintly surrounded with black stippling; dorsal surface of soft parts of body olive having black marks and patches of grayish; webbing on limbs having golden or yellowish hue, brighter distally; interorbital region brown; black-bordered, postocular stripe orange-cream; snout and side of head olive having pale areas of orange-cream; iris cream having black stripe; yellowish at juncture of dark dorsal and pale ventral coloration with orangish tinge on forelimbs and head; tail pale brown or tan, flanked by black borders that suffuse laterally into lemon-yellow; undersurface whitish, pale yellow on neck, bluish-gray on throat.
Comparisons.—T. s. pallidusmost closely resemblesT. s. guadalupensis, but can be distinguished from that subspecies in having small white tubercles, rarely two millimeters in diameter, on a pale background, that are not surrounded by blackish ocelli, and are usually absent, or not conspicuous on the anterior third of the carapace in adult males; also there are usually no conspicuous white tubercles or dots on the anterior third of the carapace in hatchlings. Many adult males ofpallidusfrom the Brazos and some from the Trinity River drainages often have dusky or black ocelli surrounding the white dots posteriorly on the carapace; males from these river systems may be distinguished fromguadalupensisin having most, if not all, white dots on the anterior half of the carapace smaller than those posteriorly, and a pale brown carapace (in life, usually darker inguadalupensis).T. s. pallidus(andguadalupensis) is distinguished fromemoryiin lacking a widened pale rim posteriorly, and in having small white spots on the anterior half of the carapace.T. s. pallidusresemblesguadalupensisandemoryiin having white spots on the carapace in adult males.T. s. pallidusdiffers fromspinifer,hartwegiandasperin lacking blackish dots or ocelli that occur in the center of[526]the carapace.T. s. pallidusresemblesemoryibut differs fromguadalupensisin lacking black ocelli surrounding the white spots.T. s. pallidusresemblesspinifer,hartwegiandasperbut differs fromguadalupensisandemoryiin having tubercles along the anterior edge of the carapace that are conical having sharp tips in males, and conical in large females.
T. s. pallidusresemblesspiniferandhartwegibut differs from the other subspecies in having a narrow head.T. s. pallidusdiffers fromemoryibut resembles the other subspecies in having a wider carapace.T. s. pallidusresemblesemoryiandguadalupensis, and differs from the other subspecies in having the carapace widest farther posterior than one-half the length of the carapace. The snout ofpallidusandguadalupensisis shorter than inspiniferandhartwegi, but longer than inemoryi.T. s. pallidusdiffers fromasperbut resembles the other subspecies in having a relatively long plastron.
Remarks.—Intergradation of the subspeciespallidusandguadalupensisis of a clinal nature in which populations successively show a gradual resemblance toguadalupensisfrom western Louisiana and eastern Texas westward to central Texas. Because the sharpest break in this cline of characters occurs between the Colorado and Brazos River drainages, the turtles living in the Brazos River drainage and eastward are referred topallidus, whereas those in the Colorado River drainage and westward are referred toguadalupensis. For further comments on intergradation between these two subspecies, see the account ofT. s. guadalupensis.
Taylor (1935:217-18) reported on some specimens ofAmyda spiniferathat were obtained by Mr. R. E. McEntyre in "… the spring and summer of 1926, chiefly about Lewisville, Lafayette County (Arkansas)." Of the catalog numbers listed by Taylor from Lewisville, 58 (KU, alcoholic) representpallidus. Three, having the same locality data, have features that are characteristic ofhartwegi. KU 2944 (one of three specimens having this catalog number) is a female having a pale, mottled and blotched carapace approximately one foot in length; there are remnants of two dark ocelli, and many widely-scattered, well-defined dark spots near the periphery of the carapace. KU 2963 (one of three specimens having this catalog number) is an adult male that has solid, blackish dots on the entire surface of the carapace. KU 2964 (one of two specimens with this catalog number) is an adult male that has ocelli approximately five millimeters in diameter on the carapace (indistinct in center of carapace).
Lewisville is situated in the drainage basin of the Red River and is approximately eight miles east of the Red River and 30 miles west of the westernmost tributary of the Ouachita River drainage.T. s. pallidusoccurs in the Red River drainage;hartwegioccurs in the Ouachita River drainage. Perhaps there is intergradation betweenpallidusandhartwegiin the intervening streams. There is no data to indicate from which river or stream each specimen obtained by McEntyre came; one would presume that all specimens came from the Red River drainage. But this is not certain. Certainly the 47 specimens designated herein aspalliduscame from the Red River drainage. I suspect that KU 2944, 2963 and 2964 were obtained from tributaries of the Ouachita River drainage.
T. s. pallidusintergrades with thespinifer-hartwegipopulation where the Red River joins the Mississippi River in the lower Mississippi Valley in Louisiana. The majority of 13 juvenal specimens from the Red River near Shaw, Concordia[527]Parish, Louisiana (USNM 99862-69, 99871-75), resemblepallidusin having inconspicuous white tubercles on a pale brown carapace. The white tubercles are conspicuous in USNM 99871. Some specimens have a few small dark dots confined to the margin of the carapace, as do some "variant" individuals from well within the geographic range ofpallidus. USNM 99865 is referred tohartwegibecause the carapace is covered with dark ocelli approximately one millimeter in diameter. Some specimens from farther west in the Red River drainage are referred tohartwegi. One (USNM 100420) of three from Natchitoches Parish, Louisiana (TU 5763, USNM 100420-21), having blackish dots on the carapace, is applicable tohartwegi. Of two turtles from Grant Parish, Louisiana (TU 5647, 12735), only 12735 has dark dots and ocelli (hartwegi). One specimen from Rapides Parish, Louisiana (TU 14040), having dark dots on the entire surface of the carapace, is referred tohartwegi.
Most specimens from the lower Atchafalaya River drainage are referable topallidus. Eastward, intergradation occurs with thespinifer-hartwegipopulation; USNM 100089-90 from Assumption Parish, near Napoleonville, Louisiana, are referred topallidus. TU 11983, from Bayou Lafourche, Raceland, La Fourche Parish, and TU 13698.11, from Bayou Gauche in St. Charles Parish, Louisiana, are juvenal males that combine the characteristics ofpallidusandhartwegi; the carapaces are covered with blackish spots and posteriorly have distinct whitish dots. The population in the Atchafalaya River more closely resemblespallidusthan it doeshartwegiorspinifer. In former times the Atchafalaya River was presumably continuous solely with the Red River (inhabited bypallidus). Now, these two rivers and the Mississippi River are interconnected in east-central Louisiana. A large volume of water of the Mississippi drainage is conveyed to the Gulf of Mexico by the Atchafalaya, and someone has said that by approximately 1975, unless man interferes, two-thirds to three-fourths of the total volume of water of the Mississippi River will be drained by the Atchafalaya. One can expect, therefore, an increase in the influence of thehartwegi-spiniferpopulation in the Atchafalaya River drainage.
Specimens examined.—Total 270, as follows:Arkansas:Lafayette: KU 2930-37, 2939-40, 2942, 2944 (two of three specimens bear this catalog number), 2945-57, 2958 (2), 2959-61, 2963 (two of three specimens bear this catalog number), 2964 (one of two specimens bears this catalog number), 2965-73, 2987-89, 3056, Lewisville.
Louisiana:Acadia: USNM 100151-59, Mermentau River.Assumption: USNM 100089-90, Bayou Lafourche, "near" Napoleonville.Beauregard: TU 1231-32, 1253-55, 1291, 13211, 13266, Sabine River, 8 mi. SW Merryville.Bienville: TU 5649-50, Lake Bistineau.Caddo: TU 381, 397-99, 469-72, 474-90, 678, 10170, Caddo Lake: TU 15818-19, Cross Lake.Calcasieu: UMMZ 92754, 5 mi. W Iowa.Cameron: TU 1122, Lacassine Wildlife Refuge.Concordia: USNM 99862-64, 99866-69, 99871-75, Red River, "near" Shaw.De Soto: SM 2374-75, Wallace Bayou.Grant: TU 5647, Lake Iatt.Iberville: USNM 83985, 2 mi. E Mounds; USNM 100239-41, Grand Lake west of White Castle; USNM 100380, Plaquemine; USNM 100412, 100414-15, 100419, Spanish Lake, "near" St. Gabriel.Jefferson Davis: Calcasieu River drainage, WTN (no number, see page 524).Natchitoches: TU 5763, Bermuda; USNM 100421, "near" Natchitoches.Sabine: TU 13210, 13212-13, 13265, 13280-82, 13303-06, Sabine River, 8 mi. SW Negreet.St. Martin: USNM 100160, Bayou Chene; USNM 100650, Atchafalaya.St. Mary: USNM 100395-97, 100404, 100409-10, Berwick Bay near Morgan City.
Oklahoma:Atoka: OU 8966, Rock Creek, 10 mi. E Atoka; OU 8978, McGee Creek, 7 mi. SW Daisy.Caddo: ANSP 100, Washita River, Fort Cobb.[528]Choctaw: OU 27126, Mayhew Creek, 2 mi. NW Boswell.Comanche: OU 4130, 4266, 5390, 8333, 12953, 19986, Wichita Mountains Wildlife Refuge.Jackson: OU 13012, 6 mi. E El Dorado.Kiowa: CNHM 15474.Le Flore: OU 6791, Kiamichi River, 8 mi. W Arkansas State Line.McCurtain: OU 2149-50, 2152, 2155, 17126-28, 17185, 2 mi. SW Smithville; USNM 70397, Red River.Marshall: KU 40175-76, 50830-31, 50847, OU 27290, 27297, 27562-63, TU 16076 (5), 16175 (6), 16662 (5), Lake Texoma, 2 mi. E Willis; KU 50832, mouth of Caney Creek, 4 mi. SW Kingston.Pushmataha: OU 2151, 2157; OU 11365, Buffalo Creek, 5 mi. NW Tuskahoma.
Texas:Archer: TU 16174, 16668-69, Lake Diversion.Bell: SM 5667-69, Nolan Creek.Bosque: KU 47121, 7 mi. below Whitney Dam, Brazos River.Brazos: BCB 4436, 10 mi. E College Station; BCB 4437, 17 mi. S College Station; BCB 4438, 4 mi. N Bryan; KU 50833, 4 mi. W College Station; SM 2556, TCWC 472, Wickson Lake; TCWC 539, Little Brazos River; TCWC 4692, 8 mi. NE Bryan; TCWC 5121, 2 mi. S College Station; TCWC no number.Clay: TCWC 7258, 8 mi. NW Ringgold, Montague County; TU 16667.1, 3 mi. W Byers.Dallas: MCZ 3987, "near" Dallas; ANSP 13243, Dallas.Donley: ANSP 13440, S of Clarendon.Eastland: KU 3132, Cisco.Galveston: TCWC 7251, Alta Loma.Harris: UMMZ 92753, Little Cypress Creek, 1 mi. N Westfield; USNM 94335-36, "near" Houston.Harrison: USNM 95386, 16.5 mi. SE Caddo Lake.Hill: TU 14169, Richland Creek, 0.7 mi. W Mertens.Leon: CNHM 46290, 5 mi. W Marquez; TCWC 8994, 8996, 6 mi. NW Normangee.Liberty: TU 14402, 14417, Trinity River, "near" jct. with Big Creek.McLennan: BCB 4665-66, 6 mi. NNE McGregor; SM no number, 2037, 2452, 2552, 2558, 2560, 2640, 5263, 6533, Lake Waco; SM 0185, Middle Bosque River; SM 2104, 6732, Upper Bosque River; SM 5072, Bull Hide Creek; UI 2399, 1.5 mi. W China Springs; UMMZ 64063, Waco; USNM 55601.Madison: TCWC 471, 517, Twin Lakes.Montgomery: TCWC 540, 3 mi. S Conroe.Nacogdoches: TNHC 14112, Legg Creek, 5 mi. S Douglass.Orange: UMMZ 117060, 3 mi. S Orange; USNM 94456-57, Orange.Randall: TTC 576, Palo Duro Canyon, 15 mi. SE Canyon.Shackelford: TU 14547, Clear Fork Brazos River, Fort Griffin State Park.Somervell: TCWC 8995, TU 14559 (4), Brazos River, 5-6 mi. E Glen Rose.Trinity: SM 2889, Groveton.Walker: TNHC 20829, 5 mi. E New Waverly.Waller: TNHC 14068, 2.7 mi. E Brazos River on US 90.Williamson: MCZ 1627 (2); TU 14348, San Gabriel River, 6.5 mi. E Georgetown.County unknown: ANSP 13448, Wichita River; USNM 7640, Brazos River.
Records in the literature.—Louisiana:Cameron: Sabine Refuge (Cagle and Chaney, 1950:386).
Oklahoma:Le Flore: 6 mi. W Page.McCurtain: 14 mi. SE Broken Bow (Trowbridge, 1937:301).
Texas:Bosque: Bosque River, "near" Valley Mills (Strecker, 1928:6).Harris: Addicks (Brown, 1950:250).Henderson: Cedar Creek (Strecker, 1926a:7).Jefferson: 12 mi. SW Port Arthur (Guidry, 1953:56).Liberty: Daisetta (Brown,loc. cit.); San Jacinto River (Strecker, 1915:15).McLennan: "near" Crawford (Brown,loc. cit.).Orange: 1 mi. N Bridge City (Guidry,loc. cit.).Tarrant: Trinity River, Fort Worth (Stejneger, 1944:66).Taylor: Abilene (KKA).Tyler: Colmisneil (Siebenrock, 1909:603).Walker: 6 mi. E Huntsville (TCWC 329, listed in card file).Wheeler: 5 mi. N Wheeler (Brown,loc cit.).
Trionyx aterWebb and LeglerBlack Softshell
Trionyx aterWebb and Legler, Univ. Kansas Sci. Bull., 40:21, pls. 1 and 2, 1960, April 20.