Chapter 5

Type.—Holotype, UMMZ 95365; alcoholic adult male; obtained at Wichita, Sedgwick County, Kansas, in May, 1945, by Robert Young.Range.—Central United States in tributaries flowing into the Mississippi River from the west, except the Red River drainage; eastern Montana, North Dakota, and southern Minnesota south to eastern Colorado, northern Oklahoma and Arkansas (see map,Fig. 19).Diagnosis.—Juvenal pattern of small ocelli, rarely as large as two millimeters[498]in diameter, or usually solid black dots that are not much larger in center of carapace than at sides (mean OD/PL, Kansas, .022); only one dark marginal line separating pale rim of carapace from dorsal ground color.Description.—Plastral length of smallest hatchling, 2.8 centimeters (USNM 9928); of largest male, 13.1 centimeters (USNM 55687); of largest female, 25.5 centimeters (KU 2283).Carapace olive, having small ocelli or black spots that are not much larger in the center of the carapace than at the sides; pale rim of carapace separated from darker ground color by one dark marginal line and not four or five times wider posteriorly than laterally; large females often having black dots at sides of carapace on mottled and blotched pattern; pattern on snout of pale, dark-bordered stripes that unite forming acute angle in front of eyes; well-defined dark markings in subocular and postlabial region; pattern contrasting with ground color on side of head; postlabial stripe broken, interrupted; pale postocular stripe having blackish borders interrupted, not joining with postlabial stripes; dorsal surface of soft parts of body having contrasting pattern, largest blackish marks on hind limbs; elongate tail of males having pale dorsolateral bands with well-defined, lower, blackish borders; patterns on soft parts of body usually obscured or absent on large females; underparts whitish, often having blackish marks, except in center of plastral area; dark marks on webbing of limbs, palms and soles; dark streaks often coincident with digits; tubercles along anterior edge of carapace small and conical on adult males, and conical or knoblike on large females; accessory, knoblike tubercles in nuchal region and in middle of carapace posteriorly on large females.Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 4.24, and exceeding 7.0 centimeters, 5.33; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.12, and exceeding 8.5 centimeters, 1.19; mean CL/PCW, 2.00; mean SL/HW, 1.30 (including subspeciesspinifer); mean CL/PL, 1.38.Variation.—Variants include: CNHM 8949, UMMZ 72511 and TU 14591 having ocelli approximately 4 millimeters in diameter that are almost solid spots; KU 17728 having pale stripes on snout that lack black, inner borders; TTC 719 (female, plastral length 20.7 cm.), having distinct pattern on snout; USNM 14535, 17823, 55684, and 123446 (from different localities) having markings confined to margins of carapace (Stejneger, 1944:66, suggested that USNM 17823 probably came from Texas); UMMZ 92667 (female, plastral length 6.7 cm.) lacking pattern on carapace.Comparisons.—T. s. hartwegican be distinguished from all other subspecies ofT. spiniferby the presence of small dots and ocelli on the carapace that are all of approximately the same size in combination with only one dark marginal line.T. s. hartwegiresemblesasperin having small blackish ocelli or dots on the carapace but differs fromasperin having only one dark marginal line.T. s. hartwegidiffers fromspiniferonly in the small size of the ocelli.T. s. hartwegiresemblesspiniferandasper, but differs frompallidus,guadalupensisandemoryiin having blackish spots and ocelli on the carapace and lacking small whitish spots.T. s. hartwegiresemblesspinifer,asperandpallidusbut differs fromguadalupensisandemoryiin having conical or knoblike tubercles on the anterior edge of the carapace on large females.[499]T. s. hartwegidiffers from the subspeciesasper,guadalupensisandemoryiin having a narrower head, and fromemoryiin having a wider carapace.T. s. hartwegiresemblesspiniferandasperbut differs from the other subspecies in having the carapace widest at a plane approximately one-half way back on the carapace.T. s. hartwegiandspiniferhave longer snouts than dopallidusandguadalupensisoremoryi.T. s. hartwegidiffers fromasperbut resembles the other subspecies in having a relatively longer plastron.Remarks.—The validity ofT. s. hartwegihas never been questioned. It intergrades withspiniferover a broad area paralleling the Mississippi River. For convenience, specimens occurring west of the Mississippi River are referred to the subspecieshartwegi.Figure 8shows much variation in size of ocelli on different individuals from the same state. For example, UMMZ 92667, plastral length 6.7 centimeters has a uniform pale brown carapace lacking any dark marks, whereas UMMZ 92652, plastral length 5.9 centimeters has some ocelli three millimeters in diameter on the carapace. Both are from Iowa. One specimen from Kansas, KU 1954 (Doniphan County, plastral length 11.8 cm.), has ocelli four millimeters in diameter, and USNM 7648 captured farther west at Fort Laramie, Wyoming, an adult male having a plastral length of 11.0 centimeters, has some ocelli five millimeters in diameter on the carapace. TTC 1090, an adult male from the panhandle of Texas has some ocelli so much as 5.5 millimeters in diameter. The size of the ocelli seemingly varies in the same local population.Specimens ofT. spiniferin the lower Mississippi Valley are intergrades. Most individuals have small black dots on the carapace; some have small ocelli (TU 7216, 7501, 11912, 12123-24) interspersed with black dots (TU 5863), others have black dots confined to the edge of the carapace (TU 157, 4539, 7105), and still others have no pattern on the carapace (TU 7506, 13698.1, 10087.6). Two large males (TU 11580, 13025) have large ocelli (approximately five mm. in diameter) that have nearly black centers. In general, there is more dark pigmentation than farther north; some specimens have extensive pigmentation on the ventral surface of the carapace and soft parts of the body (TU 156, 5648). The dorsal surface of the limbs, especially the hind limbs, have a bold, black marbling and may be almost completely black (TU 5484, 5597). Many females, not exceeding plastral lengths of 7.0 centimeters, have a pale blotched pattern of lichenlike figures or have ill-defined black dots on the carapace (TU 10087, 13698.13, 13753.15).Localities of specimens ofT. spiniferoccurring in the Mississippi River drainage in Mississippi are arbitrarily listed under the account of the subspeciesspinifer, whereas those in Louisiana (excludingpallidus) are listed under the account ofhartwegi.Neither Over (1943) nor Wheeler (1947:169) recordT. s. hartwegi, respectively, from South Dakota or North Dakota; records from the Missouri River drainage in Montana suggest the occurrence of the species in that drainage in North and South Dakota.Specimens examined.—Total, 392 as follows:Arkansas:Clay: UMMZ 70735 (2), 7 mi. S St. Francis.Crawford: USNM 95352, Lee Creek, 7 mi. NW Natural Dam.Drew: CNHM 40785.Lafayette: KU 2225-29, 2944 (one of three specimens bearing last catalog number), 2963 (one of three specimens bearing this catalog number), 2964 (one of two specimens bearing this catalog number), Lewisville (see remarks under the account of the[500]subspeciespallidus).Lawrence: CNHM 8949; CNHM 12598-600, 12602-04, TU 5855, UI 2413, Imboden; UI 2412, Black River at Powhatan.Marion: TU 14591 (6), White River at Cotter.Prairie: KU 1867, 1869, 1879, 1949-51, 2280-83, 2285-91 (2 specimens bear catalog number 2287), 2307, 2761-62, 2666, 2826, 2842, 3346-47, White River at DeValls Bluff.Pulaski: UMMZ 96540, Little Rock.Saline: USNM 17823, Saline River at Benton.Searcy: UMMZ 92755, Little Red River, 1.5 mi. SE Leslie.Yell: TU 14565, Petit Jean Creek, 10 mi. N Casa.County unknown: CNHM 28566-67, Ouachita River.Iowa:Allamakee: UMMZ 72556-58, 92642-49, Mississippi River "near" Lansing.Appanoose: UMMZ 92667, Chariton River, 4.3 mi. N. Centerville.Decatur: UMMZ 92651, Grand River, 3.5 mi. WSW Decatur.Dickinson: UMMZ 55249, Milford; UMMZ 92655, Spirit Lake Twp.Hamilton: USNM 9928, Webster City.Hardin: UMMZ 92650, Eldora.Louisa: UMMZ 92654, Muscatine Slough, 12 mi. SW Muscatine, Muscatine County.Muscatine: INHS 7675, 5.5 mi. SE Muscatine; USNM 54730-32, Fairport.Scott: CNHM 433, Davenport; UMMZ 92656, Steamboat Slough, 2 mi. N Princeton.Story: UMMZ 92653, Squaw Creek at Ames.Washington: UMMZ 92652, English River, 2 mi. E Riverside.Kansas:Anderson: KU 52286-87, 31/4mi. E,1/2mi. N Colony.Atchison: UMMZ 66939-41, Atchison.Barber: KU 17728, 4.5 mi. S Sun City; KU 41379, 41742, 6 mi. N, 3.5 mi. E Sharon; USNM 100580, Medicine River, 1 mi. S Lake City.Cherokee: KU 1323, Galena.Comanche: KU 18385, 3-4 mi. SE Arrington.Cowley: UMMZ 75963, USNM 90441-44, 91022, 100529-30, "near" Winfield.Doniphan: KU 1943, 1952-54, Doniphan Lake.Douglas: KU 1955-56, Wakarusa River; KU 40176-77, Kansas River at Lawrence.Franklin: KU 3290.Hamilton: KU 2990, Syracuse.Harper: KU 18159, 1 mi. N Harper.Kingman: USNM 95261, 2 mi. E Calista.Labette: KU 3339.Lane: KU 3738-41, Pendennis.Logan: KU 16531, Smoky Hill River, 3 mi. SW Elkader.Meade: KU 40210, Crooked Creek, 12.5 mi. S, 11/4mi. W Meade.Montgomery: KU 3731-32, Independence; KU 50856, Cherryvale Lake.Neosho: UMMZ 69294, Caneville Creek, 32 mi. N. Parsons, Labette County.Osage: KU 3294-96, Appanoose Creek.Pratt: KU 15931-32, 15934, State Fish Hatchery "near" Pratt.Riley: KU 48239, McDowell Creek, WSW Manhattan; UMMZ 64434, "near" Manhattan.Russell: KU 3289.Sedgwick: UMMZ 95363-65, Wichita.Shawnee: USNM 123446, Kansas River at Topeka.Stafford: KU 3758, Little Salt Marsh; KU 41743, 13.5 mi. N, 6 mi. E Stafford.Trego: KU 2757, 3769, Smoky Hill River, 10 mi. N (NNE) Utica, Ness County; KU 51517, Saline River, 5 mi. N,1/2mi. E Wakeeney.Wilson: KU 56744-45, Verdigris River, 1 mi. S Altoona.Woodson: KU 55295, Neosho River,1/2mi. E, 11/2mi. S Neosho Falls.County unknown: USNM 51529.Louisiana:Catahoula: TU 12629, Ouachita River, 4 mi. N Harrisonburg.Claiborne: TU 13080, Caney Lake "near" Summerfield.Concordia: KU 50849, Tensas River at Clayton; TU 16524 (3), USNM 012349, Lake Concordia; USNM 99865, Red River "near" Shaw.East Carrol: TU 827-30, 905, 5644-45, Lake Providence.Grant: TU 12735, Big Creek at Fishville, "near" Pollock.Jefferson: TU 5592-98, 7184, 10741, 10171, Mahogany Pond.Lafourche: TU 7105, 7132, 7216, 7501, 7505-07, 10087 (14), 11828-29, 11912, 11983 (2), 12123-28, 13502, 13679 (8), 13753 (22), 13766.2, Bayou Lafourche at Raceland.Morehouse: USNM 11631 (2), Mer Rouge.Natchitoches: USNM 100420, Cane River "near" Natchitoches.Orleans: TU 16169 (3), Audubon Park, New Orleans; USNM 029310, "near" New Orleans.Ouachita: TU 12916, 12954, 12970-71, 13019, 13025, Bartholomew Bayou at Sterlington; TU 5988, Monroe.Pointe Coupee: TU 153, 156-59, 165, 5484, 5513, 5518-19, 5646, 5648, 5651, USNM 100202-12, False River at New Roads.Rapides: TU 14040, Red River at Rapides.Richland: OU 25082.St. Bernard: TU 16170, Delacroix Island.St. Charles: TU 4539, 4579, 5224, 5990, 11928 (12), 13698 (16), Bayou Gauche between Paradis and Des Allemands; TU 5863, 11580, Bonnet Carre Spillway at Norco.Tensas: TU 5762, Lake St. Joseph near Newellton.Union: USNM 138946, Meridian Creek, 1 mi. E Conway; USNM 138947, Ouachita River, Alabama Landing.Parish unknown: MCZ 1622, Lake St. John (Concordia or Tensas Parish); USNM 029266, Louisiana?[501]Minnesota:Hennepin: AMNH 4759-60, Fort Snelling.Lesueur: KU 46742-43, Waterville, Lake Tetonka.Winona: USNM 59263-66, Homer.Missouri:Carter: UMMZ 70737, "near" Van Buren.Chariton: UI 17509, Triplett.Franklin: USNM 55689.Gasconade: UMMZ 95900, Bourbeuse Creek, 8 mi. S Owensville.Jefferson: USNM 95405, Glaize Creek.Lewis: USNM 59279-80, Canton.Miller: UMMZ 91929, Barren Fork Tavern Creek, 5 mi. NW Iowna.Newton: UMMZ 82822, Shoal Creek, 12 mi. W Momit.Phelps: UMMZ 91930, Bourbeuse River, 10 mi. N St. James.Reynolds: CNHM 35392, Black River at Warner Bay Spring; USNM 55688.Ripley: UMMZ 90435.Shannon: INHS 6223, Alley Spring State Park.St. Charles: USNM 93089-94, Dardenne Creek, St. Peters.St. Louis: USNM 55685-87, Mississippi River at St. Louis.Stone: USNM 55684.Washington: USNM 55690.Wayne: UI 16554, Sam A. Baker State Park; UMMZ 95879, St. Francis River at Lodi.County unknown(Wayne or Butler): UMMZ 83264, Clark National Forest, St. Francis River.Montana:Big Horn: USNM 54421, Crow Agency.Roosevelt: USNM 58, Fort Union (locality reads "Yellowstone, Fort Union"; probably the Yellowstone River near Fort Union).Wheatland: UMMZ 92005, Musselshell River near Shawmut.Yellowstone: USNM 14535, Custer.Oklahoma:Alfalfa: OU 9316, 2 mi. S Cherokee.Cleveland: OU 22973, Norman.Delaware: UMMZ 81476, Spavinaw.LeFlore: OU 16802, 1.5 mi. E Zoe.Osage: UMMZ 89628, Big Hominy Creek.Pottawatomie: OU 25175, 5 mi. SW Shawnee.Rogers: OU 7317, Verdigris River, 5 mi. W Claremore; UMMZ 81473-74, near Garnett, Tulsa County; UMMZ 81475, 4 mi. NE Inola.Sequoyah: OU 9008, 2 mi. NE Gore; TU 13885, Little Vian Creek, 1 mi. E Vian.Texas: OU 5005, 5 mi. SE Guymon.Tulsa: TU 17061, Bird Creek "near" Skiatook, Osage County.Woods: CHNM 11809, Waynoka; OU 9432, 2.5 mi. W Waynoka; OU 9579, 9581-82, 1 mi. S Waynoka.Texas:Hansford: TTC 719, 10 mi. S, 2 mi. W Gruver.Hutchinson: TTC 1090, Carson Creek, Turkey Track Ranch.Wyoming:Goshen: USNM 7648, Fort Laramie.Weston: UMMZ 78080, Beaver Creek.No Data: CNHM 21687-88, 22925. SM 142 (locality of Waco, McLennan County, Texas, believed in error). USNM 7649, 11625, 19622-23, 36412 (Illinois River).Records in the literature.—Arkansas:Benton: (Dowling, 1957:37).Chicot: Lake Chicot.Clark: Terre Noir Creek, 13 mi. W Arkadelphia.Garland: Ouachita River, Mountain Pine (Conant and Goin, 1948:7).Hempstead:Jefferson: (Dowling,loc. cit.).Lawrence: Black Rock (Dellinger and Black, 1938:46).Madison:Scott:St. Francis: (Dowling,loc. cit.).Washington: near Greenland (Dellinger and Black,loc. cit.).Colorado:Boulder: Boulder Creek, E Boulder; Boulder Creek, 6 mi. S and 1 mi. E Longmont.Larimer: Cache la Poudre River.Logan: 8 mi. NE Sterling.Morgan: Platte River "near" Fort Morgan.Otero: Purgatoire River at Higbee.Prowers: Arkansas River at Lamar.Weld: Poudre River "near" Greeley; Evans.Yuma: Bonny Dam, Republican River (Maslin, 1959:24-25).Iowa:Dickinson: Little Sioux River, Okoboji Twp. (Blanchard, 1923:24).Story: Skunk River, 5 mi. NNE Ames (Conant and Goin, 1948:9).Kansas:Allen: Petrolia (KKA).Barber: 7 mi. S Sun City.Butler: 3 mi. SE Augusta (Burt and Hoyle, 1934:198).Chase: 10 mi. SW Olpe; 7 mi. SW Saffordville (Breukelman and Smith, 1946:112).Cherokee: tributary of Spring River, 1 mi. N Riverton (Hall and Smith, 1947:451).Coffey: (Smith, 1956:160, symbol on map).Cowley: 11 mi. SE Winfield (Stejneger, 1944:55).Crawford: Pittsburg (Hall and Smith,loc. cit.).Doniphan: "near" Geary (Linsdale, 1927:81).Elk: (Smith,loc. cit.).Ellis: Big Creek (Brennan, 1934:190); Ellis (Conant and Goin, 1948:2).Franklin: Middle Creek, SE part of county (Gloyd, 1928:135).Greenwood: (Stejneger,op. cit.:54).Leavenworth: Missouri River "near" Fort Leavenworth (Brumwell, 1951:208).Lyon: 5 mi. E Emporia (Breukelman and Smith,loc. cit.).Marion: (Smith,loc. cit.).Meade: Meade County State Park,ca.13 mi. SW Meade (Tihen[502]and Sprague, 1939:505).Ness: 5.5 mi. NW Ness (Breukelman and Smith,loc. cit.).Osage: Marais des Cygnes River; Long and Jordan Creeks (Clarke, 1958:21).Reno: 6 mi. E Turon.Sedgwick: 2 mi. NE Cheney (Burt, 1935:321).Sheridan: State Lake 7 mi. NE Quinter, Gove County (Breukelman and Smith,loc. cit.).Wabaunsee: Dragoon Creek at Harveyville (Clarke, 1956:215).Wallace: (Burt, 1933:208).Wilson: Fall River,1/2mi. S Neodesha (Clarke,loc. cit.).Minnesota:Anoka:Benton:Chisago: (Breckenridge, 1944:184, symbols on map).Crow Wing: (Breckenridge,op. cit.:185).Dakota: (Hedrick and Holmes, 1956:126).Goodhue: (Breckenridge,op. cit.:184, symbol on map).Hennepin: Minneapolis; Lake Minnetonka (Breckenridge,op. cit.:187); 5 mi. N. Minneapolis (Breckenridge, 1955:5).Houston: Root River near Hokah.Lesueur: Lake Washington (Hedrick and Holmes,loc. cit.).Meeker: Swan Lake (Breckenridge, 1957:232).Pine: (Breckenridge, 1944:185).Ramsey:Rice:Sherburne:Stearns: (Breckenridge,op. cit.:184, symbols on map).Washington: just north of Stillwater (Hedrick and Holmes,loc. cit.).Winona: Winona (Breckenridge,op. cit.:187).Yellow Medicine: (Breckenridge,op. cit.:185).County unknown(Goodhue or Wabasha): Lake Pepin (Breckenridge,op. cit.:184).Missouri:Boone: east of Ashland (Henning, 1938:92).Jackson: Missouri River "near" Atherton (Anderson, 1942:219).Jefferson: Mississippi River "near" mouth Glaize Creek at Sulphur Springs; Glaize Creek at Barnhart (Boyer and Heinze, 1934:199).St. Clair: Osage River "near" Osceola.Vernon: Marmaton River, 7 mi. N Moundville (Conant and Goin, 1948:9).Montana: Yellowstone River (Conant and Goin, 1948:9).Nebraska:Adams: 1 mi. N Ayr (Hudson, 1942:101).Dawson: 2 mi. SE Gothenburg (Gehlbach and Collette, 1959:142).Franklin: 2 mi. SW Naponee.Gage: 1 mi. W Barnston.Hitchcock: 3 mi. E Stratton.Holt: Elkhorn River "near" Atkinson.Lancaster: Lincoln (Hudson,loc. cit.).Lincoln: 1 mi. S Sutherland (Gehlbach and Collette,loc. cit.).Red Willow: 14 mi. NW McCook.Richardson: 2 mi. S Rulo.Wheeler: 2 mi. W Ericson (Hudson,loc. cit.).Oklahoma:LeFlore: Wister (Conant and Goin, 1948:9); Shady Pointe (KKA); Poteau River, 6.5 mi. W Heavener (Trowbridge, 1937:301).Tulsa: Arkansas River "near" Tulsa (Force, 1930:38).Wyoming:Goshen: Platte River (Conant and Goin, 1948:10).

Type.—Holotype, UMMZ 95365; alcoholic adult male; obtained at Wichita, Sedgwick County, Kansas, in May, 1945, by Robert Young.

Range.—Central United States in tributaries flowing into the Mississippi River from the west, except the Red River drainage; eastern Montana, North Dakota, and southern Minnesota south to eastern Colorado, northern Oklahoma and Arkansas (see map,Fig. 19).

Diagnosis.—Juvenal pattern of small ocelli, rarely as large as two millimeters[498]in diameter, or usually solid black dots that are not much larger in center of carapace than at sides (mean OD/PL, Kansas, .022); only one dark marginal line separating pale rim of carapace from dorsal ground color.

Description.—Plastral length of smallest hatchling, 2.8 centimeters (USNM 9928); of largest male, 13.1 centimeters (USNM 55687); of largest female, 25.5 centimeters (KU 2283).

Carapace olive, having small ocelli or black spots that are not much larger in the center of the carapace than at the sides; pale rim of carapace separated from darker ground color by one dark marginal line and not four or five times wider posteriorly than laterally; large females often having black dots at sides of carapace on mottled and blotched pattern; pattern on snout of pale, dark-bordered stripes that unite forming acute angle in front of eyes; well-defined dark markings in subocular and postlabial region; pattern contrasting with ground color on side of head; postlabial stripe broken, interrupted; pale postocular stripe having blackish borders interrupted, not joining with postlabial stripes; dorsal surface of soft parts of body having contrasting pattern, largest blackish marks on hind limbs; elongate tail of males having pale dorsolateral bands with well-defined, lower, blackish borders; patterns on soft parts of body usually obscured or absent on large females; underparts whitish, often having blackish marks, except in center of plastral area; dark marks on webbing of limbs, palms and soles; dark streaks often coincident with digits; tubercles along anterior edge of carapace small and conical on adult males, and conical or knoblike on large females; accessory, knoblike tubercles in nuchal region and in middle of carapace posteriorly on large females.

Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 4.24, and exceeding 7.0 centimeters, 5.33; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.12, and exceeding 8.5 centimeters, 1.19; mean CL/PCW, 2.00; mean SL/HW, 1.30 (including subspeciesspinifer); mean CL/PL, 1.38.

Variation.—Variants include: CNHM 8949, UMMZ 72511 and TU 14591 having ocelli approximately 4 millimeters in diameter that are almost solid spots; KU 17728 having pale stripes on snout that lack black, inner borders; TTC 719 (female, plastral length 20.7 cm.), having distinct pattern on snout; USNM 14535, 17823, 55684, and 123446 (from different localities) having markings confined to margins of carapace (Stejneger, 1944:66, suggested that USNM 17823 probably came from Texas); UMMZ 92667 (female, plastral length 6.7 cm.) lacking pattern on carapace.

Comparisons.—T. s. hartwegican be distinguished from all other subspecies ofT. spiniferby the presence of small dots and ocelli on the carapace that are all of approximately the same size in combination with only one dark marginal line.T. s. hartwegiresemblesasperin having small blackish ocelli or dots on the carapace but differs fromasperin having only one dark marginal line.T. s. hartwegidiffers fromspiniferonly in the small size of the ocelli.T. s. hartwegiresemblesspiniferandasper, but differs frompallidus,guadalupensisandemoryiin having blackish spots and ocelli on the carapace and lacking small whitish spots.T. s. hartwegiresemblesspinifer,asperandpallidusbut differs fromguadalupensisandemoryiin having conical or knoblike tubercles on the anterior edge of the carapace on large females.

[499]

T. s. hartwegidiffers from the subspeciesasper,guadalupensisandemoryiin having a narrower head, and fromemoryiin having a wider carapace.T. s. hartwegiresemblesspiniferandasperbut differs from the other subspecies in having the carapace widest at a plane approximately one-half way back on the carapace.T. s. hartwegiandspiniferhave longer snouts than dopallidusandguadalupensisoremoryi.T. s. hartwegidiffers fromasperbut resembles the other subspecies in having a relatively longer plastron.

Remarks.—The validity ofT. s. hartwegihas never been questioned. It intergrades withspiniferover a broad area paralleling the Mississippi River. For convenience, specimens occurring west of the Mississippi River are referred to the subspecieshartwegi.Figure 8shows much variation in size of ocelli on different individuals from the same state. For example, UMMZ 92667, plastral length 6.7 centimeters has a uniform pale brown carapace lacking any dark marks, whereas UMMZ 92652, plastral length 5.9 centimeters has some ocelli three millimeters in diameter on the carapace. Both are from Iowa. One specimen from Kansas, KU 1954 (Doniphan County, plastral length 11.8 cm.), has ocelli four millimeters in diameter, and USNM 7648 captured farther west at Fort Laramie, Wyoming, an adult male having a plastral length of 11.0 centimeters, has some ocelli five millimeters in diameter on the carapace. TTC 1090, an adult male from the panhandle of Texas has some ocelli so much as 5.5 millimeters in diameter. The size of the ocelli seemingly varies in the same local population.

Specimens ofT. spiniferin the lower Mississippi Valley are intergrades. Most individuals have small black dots on the carapace; some have small ocelli (TU 7216, 7501, 11912, 12123-24) interspersed with black dots (TU 5863), others have black dots confined to the edge of the carapace (TU 157, 4539, 7105), and still others have no pattern on the carapace (TU 7506, 13698.1, 10087.6). Two large males (TU 11580, 13025) have large ocelli (approximately five mm. in diameter) that have nearly black centers. In general, there is more dark pigmentation than farther north; some specimens have extensive pigmentation on the ventral surface of the carapace and soft parts of the body (TU 156, 5648). The dorsal surface of the limbs, especially the hind limbs, have a bold, black marbling and may be almost completely black (TU 5484, 5597). Many females, not exceeding plastral lengths of 7.0 centimeters, have a pale blotched pattern of lichenlike figures or have ill-defined black dots on the carapace (TU 10087, 13698.13, 13753.15).

Localities of specimens ofT. spiniferoccurring in the Mississippi River drainage in Mississippi are arbitrarily listed under the account of the subspeciesspinifer, whereas those in Louisiana (excludingpallidus) are listed under the account ofhartwegi.

Neither Over (1943) nor Wheeler (1947:169) recordT. s. hartwegi, respectively, from South Dakota or North Dakota; records from the Missouri River drainage in Montana suggest the occurrence of the species in that drainage in North and South Dakota.

Specimens examined.—Total, 392 as follows:Arkansas:Clay: UMMZ 70735 (2), 7 mi. S St. Francis.Crawford: USNM 95352, Lee Creek, 7 mi. NW Natural Dam.Drew: CNHM 40785.Lafayette: KU 2225-29, 2944 (one of three specimens bearing last catalog number), 2963 (one of three specimens bearing this catalog number), 2964 (one of two specimens bearing this catalog number), Lewisville (see remarks under the account of the[500]subspeciespallidus).Lawrence: CNHM 8949; CNHM 12598-600, 12602-04, TU 5855, UI 2413, Imboden; UI 2412, Black River at Powhatan.Marion: TU 14591 (6), White River at Cotter.Prairie: KU 1867, 1869, 1879, 1949-51, 2280-83, 2285-91 (2 specimens bear catalog number 2287), 2307, 2761-62, 2666, 2826, 2842, 3346-47, White River at DeValls Bluff.Pulaski: UMMZ 96540, Little Rock.Saline: USNM 17823, Saline River at Benton.Searcy: UMMZ 92755, Little Red River, 1.5 mi. SE Leslie.Yell: TU 14565, Petit Jean Creek, 10 mi. N Casa.County unknown: CNHM 28566-67, Ouachita River.

Iowa:Allamakee: UMMZ 72556-58, 92642-49, Mississippi River "near" Lansing.Appanoose: UMMZ 92667, Chariton River, 4.3 mi. N. Centerville.Decatur: UMMZ 92651, Grand River, 3.5 mi. WSW Decatur.Dickinson: UMMZ 55249, Milford; UMMZ 92655, Spirit Lake Twp.Hamilton: USNM 9928, Webster City.Hardin: UMMZ 92650, Eldora.Louisa: UMMZ 92654, Muscatine Slough, 12 mi. SW Muscatine, Muscatine County.Muscatine: INHS 7675, 5.5 mi. SE Muscatine; USNM 54730-32, Fairport.Scott: CNHM 433, Davenport; UMMZ 92656, Steamboat Slough, 2 mi. N Princeton.Story: UMMZ 92653, Squaw Creek at Ames.Washington: UMMZ 92652, English River, 2 mi. E Riverside.

Kansas:Anderson: KU 52286-87, 31/4mi. E,1/2mi. N Colony.Atchison: UMMZ 66939-41, Atchison.Barber: KU 17728, 4.5 mi. S Sun City; KU 41379, 41742, 6 mi. N, 3.5 mi. E Sharon; USNM 100580, Medicine River, 1 mi. S Lake City.Cherokee: KU 1323, Galena.Comanche: KU 18385, 3-4 mi. SE Arrington.Cowley: UMMZ 75963, USNM 90441-44, 91022, 100529-30, "near" Winfield.Doniphan: KU 1943, 1952-54, Doniphan Lake.Douglas: KU 1955-56, Wakarusa River; KU 40176-77, Kansas River at Lawrence.Franklin: KU 3290.Hamilton: KU 2990, Syracuse.Harper: KU 18159, 1 mi. N Harper.Kingman: USNM 95261, 2 mi. E Calista.Labette: KU 3339.Lane: KU 3738-41, Pendennis.Logan: KU 16531, Smoky Hill River, 3 mi. SW Elkader.Meade: KU 40210, Crooked Creek, 12.5 mi. S, 11/4mi. W Meade.Montgomery: KU 3731-32, Independence; KU 50856, Cherryvale Lake.Neosho: UMMZ 69294, Caneville Creek, 32 mi. N. Parsons, Labette County.Osage: KU 3294-96, Appanoose Creek.Pratt: KU 15931-32, 15934, State Fish Hatchery "near" Pratt.Riley: KU 48239, McDowell Creek, WSW Manhattan; UMMZ 64434, "near" Manhattan.Russell: KU 3289.Sedgwick: UMMZ 95363-65, Wichita.Shawnee: USNM 123446, Kansas River at Topeka.Stafford: KU 3758, Little Salt Marsh; KU 41743, 13.5 mi. N, 6 mi. E Stafford.Trego: KU 2757, 3769, Smoky Hill River, 10 mi. N (NNE) Utica, Ness County; KU 51517, Saline River, 5 mi. N,1/2mi. E Wakeeney.Wilson: KU 56744-45, Verdigris River, 1 mi. S Altoona.Woodson: KU 55295, Neosho River,1/2mi. E, 11/2mi. S Neosho Falls.County unknown: USNM 51529.

Louisiana:Catahoula: TU 12629, Ouachita River, 4 mi. N Harrisonburg.Claiborne: TU 13080, Caney Lake "near" Summerfield.Concordia: KU 50849, Tensas River at Clayton; TU 16524 (3), USNM 012349, Lake Concordia; USNM 99865, Red River "near" Shaw.East Carrol: TU 827-30, 905, 5644-45, Lake Providence.Grant: TU 12735, Big Creek at Fishville, "near" Pollock.Jefferson: TU 5592-98, 7184, 10741, 10171, Mahogany Pond.Lafourche: TU 7105, 7132, 7216, 7501, 7505-07, 10087 (14), 11828-29, 11912, 11983 (2), 12123-28, 13502, 13679 (8), 13753 (22), 13766.2, Bayou Lafourche at Raceland.Morehouse: USNM 11631 (2), Mer Rouge.Natchitoches: USNM 100420, Cane River "near" Natchitoches.Orleans: TU 16169 (3), Audubon Park, New Orleans; USNM 029310, "near" New Orleans.Ouachita: TU 12916, 12954, 12970-71, 13019, 13025, Bartholomew Bayou at Sterlington; TU 5988, Monroe.Pointe Coupee: TU 153, 156-59, 165, 5484, 5513, 5518-19, 5646, 5648, 5651, USNM 100202-12, False River at New Roads.Rapides: TU 14040, Red River at Rapides.Richland: OU 25082.St. Bernard: TU 16170, Delacroix Island.St. Charles: TU 4539, 4579, 5224, 5990, 11928 (12), 13698 (16), Bayou Gauche between Paradis and Des Allemands; TU 5863, 11580, Bonnet Carre Spillway at Norco.Tensas: TU 5762, Lake St. Joseph near Newellton.Union: USNM 138946, Meridian Creek, 1 mi. E Conway; USNM 138947, Ouachita River, Alabama Landing.Parish unknown: MCZ 1622, Lake St. John (Concordia or Tensas Parish); USNM 029266, Louisiana?

[501]

Minnesota:Hennepin: AMNH 4759-60, Fort Snelling.Lesueur: KU 46742-43, Waterville, Lake Tetonka.Winona: USNM 59263-66, Homer.

Missouri:Carter: UMMZ 70737, "near" Van Buren.Chariton: UI 17509, Triplett.Franklin: USNM 55689.Gasconade: UMMZ 95900, Bourbeuse Creek, 8 mi. S Owensville.Jefferson: USNM 95405, Glaize Creek.Lewis: USNM 59279-80, Canton.Miller: UMMZ 91929, Barren Fork Tavern Creek, 5 mi. NW Iowna.Newton: UMMZ 82822, Shoal Creek, 12 mi. W Momit.Phelps: UMMZ 91930, Bourbeuse River, 10 mi. N St. James.Reynolds: CNHM 35392, Black River at Warner Bay Spring; USNM 55688.Ripley: UMMZ 90435.Shannon: INHS 6223, Alley Spring State Park.St. Charles: USNM 93089-94, Dardenne Creek, St. Peters.St. Louis: USNM 55685-87, Mississippi River at St. Louis.Stone: USNM 55684.Washington: USNM 55690.Wayne: UI 16554, Sam A. Baker State Park; UMMZ 95879, St. Francis River at Lodi.County unknown(Wayne or Butler): UMMZ 83264, Clark National Forest, St. Francis River.

Montana:Big Horn: USNM 54421, Crow Agency.Roosevelt: USNM 58, Fort Union (locality reads "Yellowstone, Fort Union"; probably the Yellowstone River near Fort Union).Wheatland: UMMZ 92005, Musselshell River near Shawmut.Yellowstone: USNM 14535, Custer.

Oklahoma:Alfalfa: OU 9316, 2 mi. S Cherokee.Cleveland: OU 22973, Norman.Delaware: UMMZ 81476, Spavinaw.LeFlore: OU 16802, 1.5 mi. E Zoe.Osage: UMMZ 89628, Big Hominy Creek.Pottawatomie: OU 25175, 5 mi. SW Shawnee.Rogers: OU 7317, Verdigris River, 5 mi. W Claremore; UMMZ 81473-74, near Garnett, Tulsa County; UMMZ 81475, 4 mi. NE Inola.Sequoyah: OU 9008, 2 mi. NE Gore; TU 13885, Little Vian Creek, 1 mi. E Vian.Texas: OU 5005, 5 mi. SE Guymon.Tulsa: TU 17061, Bird Creek "near" Skiatook, Osage County.Woods: CHNM 11809, Waynoka; OU 9432, 2.5 mi. W Waynoka; OU 9579, 9581-82, 1 mi. S Waynoka.

Texas:Hansford: TTC 719, 10 mi. S, 2 mi. W Gruver.Hutchinson: TTC 1090, Carson Creek, Turkey Track Ranch.

Wyoming:Goshen: USNM 7648, Fort Laramie.Weston: UMMZ 78080, Beaver Creek.

No Data: CNHM 21687-88, 22925. SM 142 (locality of Waco, McLennan County, Texas, believed in error). USNM 7649, 11625, 19622-23, 36412 (Illinois River).

Records in the literature.—Arkansas:Benton: (Dowling, 1957:37).Chicot: Lake Chicot.Clark: Terre Noir Creek, 13 mi. W Arkadelphia.Garland: Ouachita River, Mountain Pine (Conant and Goin, 1948:7).Hempstead:Jefferson: (Dowling,loc. cit.).Lawrence: Black Rock (Dellinger and Black, 1938:46).Madison:Scott:St. Francis: (Dowling,loc. cit.).Washington: near Greenland (Dellinger and Black,loc. cit.).

Colorado:Boulder: Boulder Creek, E Boulder; Boulder Creek, 6 mi. S and 1 mi. E Longmont.Larimer: Cache la Poudre River.Logan: 8 mi. NE Sterling.Morgan: Platte River "near" Fort Morgan.Otero: Purgatoire River at Higbee.Prowers: Arkansas River at Lamar.Weld: Poudre River "near" Greeley; Evans.Yuma: Bonny Dam, Republican River (Maslin, 1959:24-25).

Iowa:Dickinson: Little Sioux River, Okoboji Twp. (Blanchard, 1923:24).Story: Skunk River, 5 mi. NNE Ames (Conant and Goin, 1948:9).

Kansas:Allen: Petrolia (KKA).Barber: 7 mi. S Sun City.Butler: 3 mi. SE Augusta (Burt and Hoyle, 1934:198).Chase: 10 mi. SW Olpe; 7 mi. SW Saffordville (Breukelman and Smith, 1946:112).Cherokee: tributary of Spring River, 1 mi. N Riverton (Hall and Smith, 1947:451).Coffey: (Smith, 1956:160, symbol on map).Cowley: 11 mi. SE Winfield (Stejneger, 1944:55).Crawford: Pittsburg (Hall and Smith,loc. cit.).Doniphan: "near" Geary (Linsdale, 1927:81).Elk: (Smith,loc. cit.).Ellis: Big Creek (Brennan, 1934:190); Ellis (Conant and Goin, 1948:2).Franklin: Middle Creek, SE part of county (Gloyd, 1928:135).Greenwood: (Stejneger,op. cit.:54).Leavenworth: Missouri River "near" Fort Leavenworth (Brumwell, 1951:208).Lyon: 5 mi. E Emporia (Breukelman and Smith,loc. cit.).Marion: (Smith,loc. cit.).Meade: Meade County State Park,ca.13 mi. SW Meade (Tihen[502]and Sprague, 1939:505).Ness: 5.5 mi. NW Ness (Breukelman and Smith,loc. cit.).Osage: Marais des Cygnes River; Long and Jordan Creeks (Clarke, 1958:21).Reno: 6 mi. E Turon.Sedgwick: 2 mi. NE Cheney (Burt, 1935:321).Sheridan: State Lake 7 mi. NE Quinter, Gove County (Breukelman and Smith,loc. cit.).Wabaunsee: Dragoon Creek at Harveyville (Clarke, 1956:215).Wallace: (Burt, 1933:208).Wilson: Fall River,1/2mi. S Neodesha (Clarke,loc. cit.).

Minnesota:Anoka:Benton:Chisago: (Breckenridge, 1944:184, symbols on map).Crow Wing: (Breckenridge,op. cit.:185).Dakota: (Hedrick and Holmes, 1956:126).Goodhue: (Breckenridge,op. cit.:184, symbol on map).Hennepin: Minneapolis; Lake Minnetonka (Breckenridge,op. cit.:187); 5 mi. N. Minneapolis (Breckenridge, 1955:5).Houston: Root River near Hokah.Lesueur: Lake Washington (Hedrick and Holmes,loc. cit.).Meeker: Swan Lake (Breckenridge, 1957:232).Pine: (Breckenridge, 1944:185).Ramsey:Rice:Sherburne:Stearns: (Breckenridge,op. cit.:184, symbols on map).Washington: just north of Stillwater (Hedrick and Holmes,loc. cit.).Winona: Winona (Breckenridge,op. cit.:187).Yellow Medicine: (Breckenridge,op. cit.:185).County unknown(Goodhue or Wabasha): Lake Pepin (Breckenridge,op. cit.:184).

Missouri:Boone: east of Ashland (Henning, 1938:92).Jackson: Missouri River "near" Atherton (Anderson, 1942:219).Jefferson: Mississippi River "near" mouth Glaize Creek at Sulphur Springs; Glaize Creek at Barnhart (Boyer and Heinze, 1934:199).St. Clair: Osage River "near" Osceola.Vernon: Marmaton River, 7 mi. N Moundville (Conant and Goin, 1948:9).

Montana: Yellowstone River (Conant and Goin, 1948:9).

Nebraska:Adams: 1 mi. N Ayr (Hudson, 1942:101).Dawson: 2 mi. SE Gothenburg (Gehlbach and Collette, 1959:142).Franklin: 2 mi. SW Naponee.Gage: 1 mi. W Barnston.Hitchcock: 3 mi. E Stratton.Holt: Elkhorn River "near" Atkinson.Lancaster: Lincoln (Hudson,loc. cit.).Lincoln: 1 mi. S Sutherland (Gehlbach and Collette,loc. cit.).Red Willow: 14 mi. NW McCook.Richardson: 2 mi. S Rulo.Wheeler: 2 mi. W Ericson (Hudson,loc. cit.).

Oklahoma:LeFlore: Wister (Conant and Goin, 1948:9); Shady Pointe (KKA); Poteau River, 6.5 mi. W Heavener (Trowbridge, 1937:301).Tulsa: Arkansas River "near" Tulsa (Force, 1930:38).

Wyoming:Goshen: Platte River (Conant and Goin, 1948:10).

Trionyx spinifer asper(Agassiz)Gulf Coast Spiny Softshell

Plates37and38

Aspidonectes asperAgassiz, Contr. Nat. Hist. United States, 1(Pt. 2):405; 2(Pt. 3):pl. 6, fig. 3, 1857.

Trionyx spinifer asperSchwartz, Charleston Mus. Leaflet, No. 26:17, pls. 1-3, map 2, May, 1956.

Platypeltis agassiziiBaur, Amer. Nat., 22:1121, 1888.

Type.—Lectotype, MCZ 1597; alcoholic female; locality designated as Pearl River, Columbus, Marion County, Mississippi; received from Mr. Winthrop Sargent of Natchez, Mississippi.Range.—Southeastern United States except peninsular Florida from the Florida Parishes of Louisiana east to southern North Carolina; Gulf Coast drainage including that of Lake Pontchartrain, Louisiana, eastward to the Apalachicola River system, and Atlantic Coast drainage including that of the Altamaha River in Georgia northward to the Pee Dee River drainage in South Carolina (see map,Fig 19).[503]Diagnosis.—Juvenal pattern of black ocelli and spots, and two or more black, interrupted, lines paralleling rear margin of carapace; pale postocular and postlabial stripes often united on side of head; length of plastron short.Description.—Plastral length of smallest hatchling, 2.9 centimeters (USNM 134244); of largest male, 13.2 centimeters (TU 17117); of largest female, 27.0 centimeters (TU 13474).Blackish marginal rings on carapace number two, three or four posteriorly, but decrease in number anteriorly; segments of marginal rings may extend to nuchal region; marginal rings increasingly interrupted inwardly; pattern of hatchlings having well-defined marginal rings that are not extensively interrupted (often males), or having marginal rings broken into small segments or series of dots, and pale outer margin of carapace marked by ill-defined, hazy, inner border (often females); conspicuous marginal rings often lacking on hatchling females; pale rim of carapace not four or five times wider posteriorly than laterally; carapace having blackish dots, spots, small ocelli or a combination thereof; marks on carapace of slightly varying sizes, some occasionally barlike (usually males); some hatchling females showing pale, irregular blotching on carapace, often characterized by small lichenlike figures superimposed on blackish dots.Striping on snout variable; pale, dark-bordered stripes usually unite in front of eyes and form right or acute angle; medial dark borders of pale stripes on snout not joined anteriorly, broken into segments or dots, reduced to single median line, united to form straight line connecting anterior margins of orbits (usually with slight medial indentation), or absent; pale postocular and postlabial stripes often joined, relationship variable and on either side of head; side of head with or without dark markings, sometimes a pale subocular blotch bordered below by a dark line; pattern on dorsal portions of soft parts of body contrasting, less so on limbs of hatchlings; pattern of irregular dark marks, dark streaks usually coincident with digits; longitudinal streaks often occur on neck; elongate tail of adult males usually having well-defined, dorsolateral, pale bands with dark lower border more diffuse than upper border.Underparts whitish often with dusky markings on rear of carapace or in region of bridge; blackish marks often on webbing and portions of soles and palms, and chin and throat.Small conical tubercles along anterior edge of carapace on adult males; remnants of juvenal pattern usually present on carapace of large females; conical or knoblike tubercles on anterior edge of carapace of large females; accessory knoblike tubercles in nuchal region (a paravertebral pair usually most prominent), and posteriorly in middle of carapace on large females.Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.87, and exceeding 7.0 centimeters, 4.94; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.11, and exceeding 8.5 centimeters, 1.16; mean CL/PCW, 1.71; mean CL/PL, 1.45.Variation.—The sex of some hatchlings can be distinguished by the pattern on the carapace (see Plate 37 for different patterns), but the sex of many hatchlings cannot be distinguished on the basis of pattern.In the early stages of this study, I thought that the pattern on the carapace differed in eastern and western populations, and that the zone of intergradation[504]was in Alabama. Adult males from the Tombigbee-Alabama river drainage and westward were noted to have blackish spots (some slightly ocellate) intermixed with few, if any, smaller blackish dots, whereas the adult males from east of the Tombigbee-Alabama river drainage had many small, black dots intermixed with slightly larger, mostly ocellate marks (see Plate 38, left, top and bottom, for contrast); also, hatchlings from western populations were never observed to have four marginal rings. On the basis of pattern, I would have thought that the individual having many ocelli, that lacks correct locality data and that is photographed by Stejneger (1944:Pl. 26), came from Georgia or South Carolina; but, the pattern (op. cit.:Pl. 27) of a specimen, probably an adult male, from South Carolina, resembles the pattern on adult males from Louisiana. The differences noted above are probably due to individual variation rather than geographic variation.Color notes taken from life of a freshly-killed adult male (TU 16071, Louisiana) are: carapace olive, spots blackish, outer rim buff; top of head olive, postocular and postlabial stripes yellow with blackish borders, stripes on snout buff with blackish borders; dorsal ground color of soft parts of body pale olive-green, larger marks blackish, ground color laterally toward juncture of pattern and immaculate undersurface, and toward insertions of neck and limbs becoming yellowish; webbing on hind limbs having reddish tinge; dorsolateral bands on tail yellow with blackish borders; undersurface whitish; chin and throat olive-green with blackish marks; becoming buff then whitish posteriorly.

Type.—Lectotype, MCZ 1597; alcoholic female; locality designated as Pearl River, Columbus, Marion County, Mississippi; received from Mr. Winthrop Sargent of Natchez, Mississippi.

Range.—Southeastern United States except peninsular Florida from the Florida Parishes of Louisiana east to southern North Carolina; Gulf Coast drainage including that of Lake Pontchartrain, Louisiana, eastward to the Apalachicola River system, and Atlantic Coast drainage including that of the Altamaha River in Georgia northward to the Pee Dee River drainage in South Carolina (see map,Fig 19).

[503]

Diagnosis.—Juvenal pattern of black ocelli and spots, and two or more black, interrupted, lines paralleling rear margin of carapace; pale postocular and postlabial stripes often united on side of head; length of plastron short.

Description.—Plastral length of smallest hatchling, 2.9 centimeters (USNM 134244); of largest male, 13.2 centimeters (TU 17117); of largest female, 27.0 centimeters (TU 13474).

Blackish marginal rings on carapace number two, three or four posteriorly, but decrease in number anteriorly; segments of marginal rings may extend to nuchal region; marginal rings increasingly interrupted inwardly; pattern of hatchlings having well-defined marginal rings that are not extensively interrupted (often males), or having marginal rings broken into small segments or series of dots, and pale outer margin of carapace marked by ill-defined, hazy, inner border (often females); conspicuous marginal rings often lacking on hatchling females; pale rim of carapace not four or five times wider posteriorly than laterally; carapace having blackish dots, spots, small ocelli or a combination thereof; marks on carapace of slightly varying sizes, some occasionally barlike (usually males); some hatchling females showing pale, irregular blotching on carapace, often characterized by small lichenlike figures superimposed on blackish dots.

Striping on snout variable; pale, dark-bordered stripes usually unite in front of eyes and form right or acute angle; medial dark borders of pale stripes on snout not joined anteriorly, broken into segments or dots, reduced to single median line, united to form straight line connecting anterior margins of orbits (usually with slight medial indentation), or absent; pale postocular and postlabial stripes often joined, relationship variable and on either side of head; side of head with or without dark markings, sometimes a pale subocular blotch bordered below by a dark line; pattern on dorsal portions of soft parts of body contrasting, less so on limbs of hatchlings; pattern of irregular dark marks, dark streaks usually coincident with digits; longitudinal streaks often occur on neck; elongate tail of adult males usually having well-defined, dorsolateral, pale bands with dark lower border more diffuse than upper border.

Underparts whitish often with dusky markings on rear of carapace or in region of bridge; blackish marks often on webbing and portions of soles and palms, and chin and throat.

Small conical tubercles along anterior edge of carapace on adult males; remnants of juvenal pattern usually present on carapace of large females; conical or knoblike tubercles on anterior edge of carapace of large females; accessory knoblike tubercles in nuchal region (a paravertebral pair usually most prominent), and posteriorly in middle of carapace on large females.

Ontogenetic variation in PL/HW, mean PL/HW of specimens having plastral lengths 7.0 centimeters or less, 3.87, and exceeding 7.0 centimeters, 4.94; ontogenetic variation in CL/CW, mean CL/CW of specimens having plastral lengths 8.5 centimeters or less, 1.11, and exceeding 8.5 centimeters, 1.16; mean CL/PCW, 1.71; mean CL/PL, 1.45.

Variation.—The sex of some hatchlings can be distinguished by the pattern on the carapace (see Plate 37 for different patterns), but the sex of many hatchlings cannot be distinguished on the basis of pattern.

In the early stages of this study, I thought that the pattern on the carapace differed in eastern and western populations, and that the zone of intergradation[504]was in Alabama. Adult males from the Tombigbee-Alabama river drainage and westward were noted to have blackish spots (some slightly ocellate) intermixed with few, if any, smaller blackish dots, whereas the adult males from east of the Tombigbee-Alabama river drainage had many small, black dots intermixed with slightly larger, mostly ocellate marks (see Plate 38, left, top and bottom, for contrast); also, hatchlings from western populations were never observed to have four marginal rings. On the basis of pattern, I would have thought that the individual having many ocelli, that lacks correct locality data and that is photographed by Stejneger (1944:Pl. 26), came from Georgia or South Carolina; but, the pattern (op. cit.:Pl. 27) of a specimen, probably an adult male, from South Carolina, resembles the pattern on adult males from Louisiana. The differences noted above are probably due to individual variation rather than geographic variation.

Color notes taken from life of a freshly-killed adult male (TU 16071, Louisiana) are: carapace olive, spots blackish, outer rim buff; top of head olive, postocular and postlabial stripes yellow with blackish borders, stripes on snout buff with blackish borders; dorsal ground color of soft parts of body pale olive-green, larger marks blackish, ground color laterally toward juncture of pattern and immaculate undersurface, and toward insertions of neck and limbs becoming yellowish; webbing on hind limbs having reddish tinge; dorsolateral bands on tail yellow with blackish borders; undersurface whitish; chin and throat olive-green with blackish marks; becoming buff then whitish posteriorly.

Fig. 20.Basicranial length and ratio of greatest diameter of internal choanae to least width of maxillary bridge (IC/MB) on 30 skulls ofT. ferox(open circles), 26 ofT. spinifer(crosses), and 12 of theagassizi-form (solid circles; half shaded circle represents holotype ofagassizi). Skulls of theagassizi-form tend to have slightly smaller internal choanae than those ofspiniferorferox.

Fig. 20.Basicranial length and ratio of greatest diameter of internal choanae to least width of maxillary bridge (IC/MB) on 30 skulls ofT. ferox(open circles), 26 ofT. spinifer(crosses), and 12 of theagassizi-form (solid circles; half shaded circle represents holotype ofagassizi). Skulls of theagassizi-form tend to have slightly smaller internal choanae than those ofspiniferorferox.

Occasional specimens have only one definite dark line paralleling the rear margin of the carapace. Schwartz (1956:16) reported that Charleston Museum No. 55.159.26 has only one solid line at the margin of the carapace, and I received an adult male (KU 47120) reported to have come from the Pearl River that is aberrant in not having more than one dark marginal line. USNM 95191, a large stuffed female from the Pearl River is mentioned by Stejneger (1944:59, Pl. 17) as having marks that "assume the form of short lines parallel[505]with the submarginal ring"; I examined this specimen and noted that it had only one dark marginal line. Stejneger (op. cit.:64) mentioned another from the Pearl River drainage, and Crenshaw and Hopkins (1955:20) wrote that some individuals from Georgia have only one dark marginal line. Presumably MCZ 1606 (now in the Albany Museum) recorded by Stejneger (op. cit.:52) asAmyda s. spiniferfrom Columbus, Georgia, is another specimen.

Fig. 21.Basicranial length and greatest width of alveolar surface of maxilla on 52 skulls ofT. spinifer(open circles) and 11 of theagassizi-form (solid circles; half shaded circle represents holotype ofagassizi). Most skulls of theagassizi-form that exceed 43 mm. in basicranial length have a more expanded, alveolar surface of the maxilla than skulls ofspiniferof approximately the same size. All skulls exceeding 50 mm. are those of females.

Fig. 21.Basicranial length and greatest width of alveolar surface of maxilla on 52 skulls ofT. spinifer(open circles) and 11 of theagassizi-form (solid circles; half shaded circle represents holotype ofagassizi). Most skulls of theagassizi-form that exceed 43 mm. in basicranial length have a more expanded, alveolar surface of the maxilla than skulls ofspiniferof approximately the same size. All skulls exceeding 50 mm. are those of females.

Some skulls of soft-shelled turtles from streams of the Atlantic Coast drainage, including the skull of the holotype ofPlatypeltis(=Trionyx)agassiziBaur (MCZ 37172,Pl. 54), show at least two differences from other skulls ofasperand from those of other subspecies ofT. spinifer.Figure 20shows that skulls ofagassizitend to have slightly smaller internal choanae (ratio IC/MB) than those ofT. spiniferandT. ferox; there is seemingly little difference between skulls offeroxandspinifer, and little, if any, ontogenetic variation.Figure 21shows that most skulls of theagassizi-form that exceed 43.0 millimeters have a more expanded, alveolar surface of the maxilla than skulls ofspiniferof approximately the same size; most skulls exceeding a basicranial length of 43.0 millimeters, and certainly all skulls exceeding 50.0 millimeters are those of females. Stejneger (1944:Pl. 30) also has provided photographs of a skull of theagassizi-form. It is of interest that of the 12agassizi-form skulls (MCZ 37172; USNM 8708, 029034, 51981, 66859, 71681, 91282, 91310-11, 92521, 92583-84) that I examined some resembleferox(Neill, 1951:9) in having the alveolar surfaces of the jaws broadened, and the greatest width at the level of the quadratojugal (Table 3, Plate 54); also, the localities of all 12 skulls are within the geographic range offerox. Skulls offerox, however, have conspicuously broadened alveolar surfaces of the jaws only when they exceed in length the largest skulls ofagassizi. The differences of skulls of theagassizi-form possibly reflect isolation in the Atlantic Coast drainage, and an adaptation in feeding habits. So far as I can ascertain, individuals occurring in rivers of the Atlantic Coast drainage in Georgia and South Carolina (referable toagassizi) do not differ consistently in external characters from individuals ofT. s. asperthat occur westward in the Apalachicola drainage.Comparisons.—Trionyx s. aspercan be distinguished from all other subspecies ofT. spiniferby usually having more than one black line paralleling[506]the rear margin of the carapace. This character and the frequent fusion of the postlabial and postocular stripes on the side of the head distinguishasperfromspiniferandhartwegi.T. s. asperdiffers frompallidus,guadalupensisandemoryiin having blackish spots and ocelli on the carapace, and lacking whitish dots or tubercles.T. s. asperresemblesspinifer,hartwegiandpallidusbut differs fromguadalupensisandemoryiin having conical tubercles along the anterior edge of the carapace in large females. For additional differences see accounts of other subspecies.Of the subspecies ofT. spinifer,asperhas a proportionately wide head that is closely approached in the subspeciesguadalupensisandemoryi;T. s. asperdiffers fromguadalupensisandemoryiin having a wider carapace, and resembleshartwegiandspinifer, but differs from the other subspecies in having the carapace widest at a plane approximately one-half way back on the carapace.T. s. asperdiffers from the other subspecies in having the shortest plastron.Remarks.—Stejneger (1944:72-74) has discussed the history of Baur'sPlatypeltis agassizi. Briefly, Agassiz's description ofPlatypeltis feroxwherein he (1857:402) states that "The young ferox [Pl. 6, fig. 3] has two or three concentric black lines separating the pale margin …," was applicable toT. s. asper. Agassiz mentioned also that the young of hisAspidonectes asper(op. cit.:406) "as in Platypeltis ferox, … has … two or three black lines separating the pale rim of the posterior margin, …"; however,A. asperwas distinguished chiefly by the "… prominent warts of the bony plates (loc. cit.)." Because the description of the pattern offeroxresembled that ofasper, the validity ofasperwas not agreed upon by all workers. Boulenger (1889:245, footnote 1) referred toasperas a species that required "… further investigation."Baur (1888:1121) realized that Agassiz's description offeroxwas not that ofTestudo feroxSchneider, and regarded the description of Agassiz as applying to a new species, which he namedPlatypeltis agassizii; Baur (op. cit.:1122) also recognizedasper, referring it to the genusAspidonectes. Baur designated a specimen from Georgia (the only individual seen by him) as the type ofagassizi(Stejneger,op. cit.:73, footnote); this specimen is now MCZ 37172. Five years later (1893:218), Baur discussed generic relationships of trionychids, seemingly only on the basis of skulls (holotype ofagassizinot mentioned), and referredagassizito the resurrected genusPelodiscusFitzinger, 1835, which was distinguished from the other two American genera that Baur recognized (PlatypeltisandAmyda) by having the "Posterior nares reduced in size by the inner and posterior extension of the maxillaries." Baur also transferredasperto the genusPlatypeltis, and restricted the type locality of that species to "Lake Concordia, La." (op. cit.:220); the type locality ofagassiziwas restricted to "Western Georgia" (loc. cit.).The name-combination,Pelodiscus agassizi, was not generally accepted. Hay (1892:144) and Siebenrock (1924:188) referredagassizito the genusTrionyx. Hay regardedagassizias a full species (see discussion by Stejneger, 1944:73), whereas Siebenrock considered it a subspecies ofspiniferus; both authors regardedasperas a synonym ofagassizi. Neitheraspernoragassiziwas mentioned in the first three editions of the Check List of North American Amphibians and Reptiles (Stejneger and Barbour, 1917, 1923, 1933); the[507]same authors in the fourth (1939:171, 172) and fifth editions (1943:212, 213) listedagassizias a full species, andasperas a subspecies ofspinifera. Stejneger (1944) used the same arrangement as set forth in the fourth and fifth editions of the Check List, and distinguishedagassizion the basis of cranial characters, namely, the small size of the internal choanae, the greater width of the alveolar surface of the lower jaw, and the position of the suture between the palatine and basisphenoid relative to the posterior edge of the temporal fossa. Neill (1951:9) regarded the peculiarities of theagassizi-type skull as inconstant, but recognizedagassizi(andasper) as a subspecies offerox. Crenshaw and Hopkins (1955) showed thatasperdid not intergrade withferox. Schwartz showed thatagassizidid not intergrade withferox, and regardedagassizias a synonym ofT. s. asper(1956:17), but stated thatagassizipossessed "wider crushing surfaces on the maxillae than doesT. s. asper, even when skulls of the same size and sex are compared" (op. cit.:9).The holotype ofPlatypeltis agassizi(MCZ 37172) is a dried adult female consisting of shell, skull and limb bones; the carapace is approximately 300 millimeters long (Schwartz,loc. cit.). I have examined only the skull of MCZ 37172 (Plate 54), and it is the largest of 12agassizi-type skulls I have seen. The basicranial length is 72.5 millimeters, and the greatest width, which occurs at the level of the quadratojugals, is 52.9 millimeters. Theagassizi-type skulls have been discussed under the subsection on variation.The type locality ofT. s. asper, Lake Concordia, Louisiana (lower Mississippi River drainage) as restricted by Baur (1893:220), is in an area of intergradation of three subspecies ofTrionyx spiniferwhere most individuals are not typical ofasper. The syntypes, the designation of MCZ 1597 as a lectotype, and Pearl River, Columbus, Marion County, Mississippi, as the type locality have been discussed elsewhere (Webb, 1960).The range ofT. s. asperoverlaps that ofT. feroxin Georgia and South Carolina. The two species remain distinct in the area of overlap of their geographic ranges (Crenshaw and Hopkins, 1955:16; Schwartz,op. cit.:5).Trionyx s. asperintergrades withT. s. hartwegiandT. s. spiniferin the lower Mississippi Valley (Conant and Goin, 1948:11).However, there are few specimens available that indicate intergradation ofasperwith thespinifer-hartwegicomplex in the lower Mississippi River drainage; this may be due to the fact thatasperinhabits waterways that do not drain into the Mississippi River. Perhaps intergradation is more prevalent than the morphological basis that I have relied upon indicates; in any event, there are few specimens that have more than one dark marginal line (which is the only character that is unique forasper) from the lower Mississippi drainage. A young male (TU 11928.9) from Bayou Gauche between Paradis and Des Allemands, St. Charles Parish, Louisiana, has a pattern on the carapace resembling that ofasper; several other small softshells (TU) are available from the same locality but none shows more than one dark marginal line. Another specimen (USNM 95192), a young female from a barrow pit of the Big Black River (Mississippi River drainage), Madison County, Mississippi, resemblesasperin having more than one marginal ring. Of three large females from Moon Lake, an ox-bow of the Mississippi River in Coatopa County, Mississippi (AMNH 5285-86, 5289), only 5289 shows evidence of two marginal lines. USNM 73669 (Greenwood, LeFlore County, Mississippi) also indicates intergradation in that the spots tend to be linear just inside the dark marginal[508]line, but the specimen more closely resembles thehartwegi-spinifercomplex rather thanasper.There seems to be little adumbration of the dark marginal lines ofasperin populations from the lower Mississippi River drainage. Blackish spots and ocelli vary in size and there are many kinds of pattern on the carapace. Soft-shelled turtles inhabiting the Mississippi River and its tributaries in Louisiana and Mississippi certainly represent an intergrading population ofspiniferandhartwegi, and, to a lesser extent, ofasper. Soft-shelled turtles inhabiting the Pearl River drainage and rivers that drain into Lake Pontchartrain immediately adjacent to the east are predominantlyasper.Specimens having localities from the Pearl River and Lake Pontchartrain drainages are listed under the account ofasperand are referred to that subspecies on the distribution map; specimens from the Mississippi drainage in Mississippi are referred tospinifer.One specimen (UMMZ 59198, Bradley County, Tennessee), from the Tennessee River drainage whereT. s. spiniferoccurs, deviates markedly fromspiniferand suggests intergradation. UMMZ 59198, plastral length 4.8 centimeters, has ocelli in the center of the carapace only two millimeters in diameter, a distinct but interrupted, second marginal ring consisting of spots, and the pale postlabial and postocular stripes in contact on both sides of the head.Specimens examined.—Total 110, as follows:Alabama:Barbour: UMMZ 113038, Chattahoochee River, Eufala.Cherokee: ANSP 24592, "near" center of Terrapin Creek.Conecuh: UMMZ 70736, Murder Creek, Castleberry.Escambia: TU 15823, Escambia River, 1 mi. N Sardine; UMMZ 70734, Escambia River at Flomaton.Henry: TU 15630, 3 mi. NW jct. Echo Farm Rd. and Rt. 136 on Echo Farm Rd.Lowndes: UMMZ 67759, Pintlalla Creek.Mobile: MCZ 1608 (2), 1608A, Mobile.Sumpter: USNM 83996, 3 mi. SE Coatopa.Tuscaloosa: TU 14673 (5), Black Warrior River, 17.5 mi. SSW Tuscaloosa; UA 52-1085, Cottondale.Walker: KU 50843, 50851, TU 17137, Mulberry Fork, Black Warrior River, 9 mi. E Jasper.Florida:Calhoun: KU 50837-38, Chipola River, 4 mi. N Scott's Ferry; TU 16689 (4), Chipola River "near" Blountstown.Escambia: TU 13474, 15869 (3), 16584, Escambia River, 1.2 mi. E Century.Okaloosa: TU 15661, Blackwater River, 4.3 mi. NW Baker on Route 4.Santa Rosa: AMNH 44621, Blackwater River, Milton.Walton: UMMZ 110421, Pond Creek, 4 mi. SW Florala, Covington County, Alabama.Georgia:Baker: TU 15889 (3), USNM 134243-48, Flint River "near" Newton; USNM 30822.Baldwin: USNM 8708, Milledgeville.Bryan: TU 15090, Canouche River, 2.3 mi. W Groveland.Chatham: USNM 51981, 92583-84, Savannah.Chattooga: UMMZ 113037, tributary of Chattooga River, Lyerly.Decatur: KU 50839-42, Flint River, 1.5 mi. S Bainbridge.Fulton: UMMZ 53037, Roswell.Lincoln: USNM 91282-83, above Price Island, Savannah River.Murray: UMMZ 59196, 9 mi. N Spring Place.Pulaski: TU 14882, Ocmulgee River, 4.3 mi. SE Hawkinsville.Richmond: USNM 66859, Augusta.Whitfield: UMMZ 74209, Cohulla Creek, Prater's Mill "near" Dalton.County unknown: MCZ 37172; UMMZ 109864, Flint River at mouth of Dry Creek; USNM 029034.Louisiana:East Baton Rouge: LSU 11, 1643-44, City Park Lake in Baton Rouge; TU 17237, Amite River "near" Baton Rouge.St. Tammany: TU 6356, headwater creek of Bayou Lacombe; TU 16071, USNM 66147, mouth of Tchefuncta Creek in Lake Pontchartrain.Tangipahoa: TU 13623, 3.1 mi. W Hammond; USNM 68054, Robert.Washington: KU 50840, 50846, TU 17117, Pearl River at Varnado.Parish unknown(East Baton Rouge or Tangipahoa): UMMZ 95614, Manchac.[509]Mississippi:Chickasaw: USNM 115981, Chookatonkchie Creek.Clarke: USNM 79350-51, 1 mi. W Melvin, Choctaw County, Alabama; USNM 100805, Enterprise.Forrest: WEB 55-586, 1 mi. S Hattiesburg.Hancock: AMNH 46780; WEB 54-651, Hickory Creek "near" Kiln.Lauderdale: UMMZ 74681, 9 mi. W Meridian; UMMZ 90130, Lake Juanita, 15 mi. W Meridian.Lawrence: KU 47120, TU 17307.1, Pearl River, 9 mi. S Monticello; USNM 7653-54, Pearl River at Monticello.Lee: CM 31904, Verona; USNM 115979, Cower's Area near Guntown.Madison: USNM 95191, 95193-94, Pearl River.Marion: MCZ 1597, Pearl River at Columbus (designated type locality).Pearl River: CM 21100, Pearl River, 20 mi. W Poplarville; TU 14362, Hobolochito Creek, 1 mi. N Picayune.Perry: WEB 55-580, Beaver Dam Creek, 1 mi. N Richton.Walthall: KU 50844, Bogue Chitto River, Dillon.South Carolina:Abbeville: USNM 7650, Abbeville? (reported by Pickens, 1927:113; locality considered in error by Stejneger, 1944:50; USNM 7650 having only one dark marginal line paralleling rear margin of carapace is possibly an aberrant specimen—see page 495 of present account).Greenwood: USNM 71681, 73668, Greenwood.McCormick: USNM 91310-12, Savannah River, 5 mi. W Plum Branch; USNM 92521, near Parksville.Richland: AMNH 70724-25, Broad River, Columbia.No Data: USNM 8359 (erroneously reported from Madison, Indiana by Yarrow, 1882:29 and Hay, 1892:145; see discussion by Cahn, 1937:200, and Stejneger, 1944:73-75); USNM 131859.Records in the literature.—Alabama:Coffee: Elba (KKA).Marengo: Tombigbee River near Demopolis.Mobile: Fig Island (Löding, 1922:47).Florida:Jackson: Chattahoochee River, 8 mi. SE Butler.Leon: Ochlocknee River, NW of Tallahassee (Goin, 1948:304).Georgia:Bartow: Etowah River below Allatoona Dam,ca.4 mi. ESE Cartersville (Crenshaw and Hopkins, 1955:15).Berrien: (Knepton, 1956:324).Emanuel: Ogeeche River (Schwartz, 1956:19).Fulton: Nancy Creek, Atlanta (Dunston, 1960:278).Gwinnett:Irwin: (Knepton,loc. cit.).Jenkins: Ogeeche River near Buckland Creek jct., 2.5 mi. S Millen.Liberty: Camp Stewart, 4 mi. N Hinesville.Morgan: Lake Rutledge (Schwartz,loc. cit.).Muscogee: Columbus (Stejneger, 1944:52).Wayne: Altamaha River, 5 mi. N Mt. Pleasant (Schwartz,loc. cit.).Wilcox: Ocmulgee River, 3-4 mi. SSE Abbeville (Crenshaw and Hopkins,op cit.:16, footnote; Schwartz,loc. cit.).Mississippi:George: Whiskey Creek (Cook, 1946:185).Harrison: near Biloxi.Jackson: Pascagoula Swamp,ca.40 mi. E. Biloxi (Corrington, 1927:101).Jones: Eastabuchie.Lee: Cain Creek Bottom.Lincoln: Old Brook Creek.Lowndes: Tombigbee River, Camp Henry Pratt and Columbus; Lake Park, Columbus.Pearl River: 21 mi. SW Poplarville; 10 mi. W Poplarville; 4 mi. W Poplarville.Wayne: Trigg Area (Cook,loc. cit.).North Carolina:Mecklenburg: Catawba River near Charlotte (Schwartz, 1956:20).South Carolina:Aiken: Savannah River, 10 mi. SW Jackson.Allendale: Savannah River, Fennell Hill, 2 mi. S US 301.Anderson: Pendleton.Bamberg: South Edisto River, Cannon's Bridge, 5 mi. from Bamberg.Berkeley: 2.5 mi. W Pinopolis.Charleston: Charleston.Clarendon: Upper Lake Marion at US 301; Lake Marion, 13 mi. SW Manning; 3.3 mi. S Jordan; 6.3 mi. S Jordan; Wyboo Creek, 8.5 mi. from Manning.Colleton: Edisto River (Schwartz, 1956:19-20).Darlington: Pee Dee River, Society Hill (Stejneger, 1944:72).Dorchester: Edisto River, 17 mi. from Summerville; Edisto River, 14 mi. W Summerville; Edisto River, 2.5 mi. S Hart's Bluff.Fairfield: 1 mi. N Peak, Newberry County.Georgetown: North Santee River, 1 mi. above US 17.McCormick: Little River near McCormick; Little River, 3 mi. NE Mt. Carmel.Laurens: Enoree River, 3 mi. S Cashville, Spartanburg County; Enoree River, 9.4 mi. N Clinton.Orangeburg: Edisto River, Orangeburg.Saluda: Batesburg; Lake Murray; Little Saluda River; 5 mi. from Saluda.County unknown: Upper Lake Santee (Schwartz,loc. cit.).

Some skulls of soft-shelled turtles from streams of the Atlantic Coast drainage, including the skull of the holotype ofPlatypeltis(=Trionyx)agassiziBaur (MCZ 37172,Pl. 54), show at least two differences from other skulls ofasperand from those of other subspecies ofT. spinifer.Figure 20shows that skulls ofagassizitend to have slightly smaller internal choanae (ratio IC/MB) than those ofT. spiniferandT. ferox; there is seemingly little difference between skulls offeroxandspinifer, and little, if any, ontogenetic variation.Figure 21shows that most skulls of theagassizi-form that exceed 43.0 millimeters have a more expanded, alveolar surface of the maxilla than skulls ofspiniferof approximately the same size; most skulls exceeding a basicranial length of 43.0 millimeters, and certainly all skulls exceeding 50.0 millimeters are those of females. Stejneger (1944:Pl. 30) also has provided photographs of a skull of theagassizi-form. It is of interest that of the 12agassizi-form skulls (MCZ 37172; USNM 8708, 029034, 51981, 66859, 71681, 91282, 91310-11, 92521, 92583-84) that I examined some resembleferox(Neill, 1951:9) in having the alveolar surfaces of the jaws broadened, and the greatest width at the level of the quadratojugal (Table 3, Plate 54); also, the localities of all 12 skulls are within the geographic range offerox. Skulls offerox, however, have conspicuously broadened alveolar surfaces of the jaws only when they exceed in length the largest skulls ofagassizi. The differences of skulls of theagassizi-form possibly reflect isolation in the Atlantic Coast drainage, and an adaptation in feeding habits. So far as I can ascertain, individuals occurring in rivers of the Atlantic Coast drainage in Georgia and South Carolina (referable toagassizi) do not differ consistently in external characters from individuals ofT. s. asperthat occur westward in the Apalachicola drainage.

Comparisons.—Trionyx s. aspercan be distinguished from all other subspecies ofT. spiniferby usually having more than one black line paralleling[506]the rear margin of the carapace. This character and the frequent fusion of the postlabial and postocular stripes on the side of the head distinguishasperfromspiniferandhartwegi.T. s. asperdiffers frompallidus,guadalupensisandemoryiin having blackish spots and ocelli on the carapace, and lacking whitish dots or tubercles.T. s. asperresemblesspinifer,hartwegiandpallidusbut differs fromguadalupensisandemoryiin having conical tubercles along the anterior edge of the carapace in large females. For additional differences see accounts of other subspecies.

Of the subspecies ofT. spinifer,asperhas a proportionately wide head that is closely approached in the subspeciesguadalupensisandemoryi;T. s. asperdiffers fromguadalupensisandemoryiin having a wider carapace, and resembleshartwegiandspinifer, but differs from the other subspecies in having the carapace widest at a plane approximately one-half way back on the carapace.T. s. asperdiffers from the other subspecies in having the shortest plastron.

Remarks.—Stejneger (1944:72-74) has discussed the history of Baur'sPlatypeltis agassizi. Briefly, Agassiz's description ofPlatypeltis feroxwherein he (1857:402) states that "The young ferox [Pl. 6, fig. 3] has two or three concentric black lines separating the pale margin …," was applicable toT. s. asper. Agassiz mentioned also that the young of hisAspidonectes asper(op. cit.:406) "as in Platypeltis ferox, … has … two or three black lines separating the pale rim of the posterior margin, …"; however,A. asperwas distinguished chiefly by the "… prominent warts of the bony plates (loc. cit.)." Because the description of the pattern offeroxresembled that ofasper, the validity ofasperwas not agreed upon by all workers. Boulenger (1889:245, footnote 1) referred toasperas a species that required "… further investigation."

Baur (1888:1121) realized that Agassiz's description offeroxwas not that ofTestudo feroxSchneider, and regarded the description of Agassiz as applying to a new species, which he namedPlatypeltis agassizii; Baur (op. cit.:1122) also recognizedasper, referring it to the genusAspidonectes. Baur designated a specimen from Georgia (the only individual seen by him) as the type ofagassizi(Stejneger,op. cit.:73, footnote); this specimen is now MCZ 37172. Five years later (1893:218), Baur discussed generic relationships of trionychids, seemingly only on the basis of skulls (holotype ofagassizinot mentioned), and referredagassizito the resurrected genusPelodiscusFitzinger, 1835, which was distinguished from the other two American genera that Baur recognized (PlatypeltisandAmyda) by having the "Posterior nares reduced in size by the inner and posterior extension of the maxillaries." Baur also transferredasperto the genusPlatypeltis, and restricted the type locality of that species to "Lake Concordia, La." (op. cit.:220); the type locality ofagassiziwas restricted to "Western Georgia" (loc. cit.).

The name-combination,Pelodiscus agassizi, was not generally accepted. Hay (1892:144) and Siebenrock (1924:188) referredagassizito the genusTrionyx. Hay regardedagassizias a full species (see discussion by Stejneger, 1944:73), whereas Siebenrock considered it a subspecies ofspiniferus; both authors regardedasperas a synonym ofagassizi. Neitheraspernoragassiziwas mentioned in the first three editions of the Check List of North American Amphibians and Reptiles (Stejneger and Barbour, 1917, 1923, 1933); the[507]same authors in the fourth (1939:171, 172) and fifth editions (1943:212, 213) listedagassizias a full species, andasperas a subspecies ofspinifera. Stejneger (1944) used the same arrangement as set forth in the fourth and fifth editions of the Check List, and distinguishedagassizion the basis of cranial characters, namely, the small size of the internal choanae, the greater width of the alveolar surface of the lower jaw, and the position of the suture between the palatine and basisphenoid relative to the posterior edge of the temporal fossa. Neill (1951:9) regarded the peculiarities of theagassizi-type skull as inconstant, but recognizedagassizi(andasper) as a subspecies offerox. Crenshaw and Hopkins (1955) showed thatasperdid not intergrade withferox. Schwartz showed thatagassizidid not intergrade withferox, and regardedagassizias a synonym ofT. s. asper(1956:17), but stated thatagassizipossessed "wider crushing surfaces on the maxillae than doesT. s. asper, even when skulls of the same size and sex are compared" (op. cit.:9).

The holotype ofPlatypeltis agassizi(MCZ 37172) is a dried adult female consisting of shell, skull and limb bones; the carapace is approximately 300 millimeters long (Schwartz,loc. cit.). I have examined only the skull of MCZ 37172 (Plate 54), and it is the largest of 12agassizi-type skulls I have seen. The basicranial length is 72.5 millimeters, and the greatest width, which occurs at the level of the quadratojugals, is 52.9 millimeters. Theagassizi-type skulls have been discussed under the subsection on variation.

The type locality ofT. s. asper, Lake Concordia, Louisiana (lower Mississippi River drainage) as restricted by Baur (1893:220), is in an area of intergradation of three subspecies ofTrionyx spiniferwhere most individuals are not typical ofasper. The syntypes, the designation of MCZ 1597 as a lectotype, and Pearl River, Columbus, Marion County, Mississippi, as the type locality have been discussed elsewhere (Webb, 1960).

The range ofT. s. asperoverlaps that ofT. feroxin Georgia and South Carolina. The two species remain distinct in the area of overlap of their geographic ranges (Crenshaw and Hopkins, 1955:16; Schwartz,op. cit.:5).Trionyx s. asperintergrades withT. s. hartwegiandT. s. spiniferin the lower Mississippi Valley (Conant and Goin, 1948:11).

However, there are few specimens available that indicate intergradation ofasperwith thespinifer-hartwegicomplex in the lower Mississippi River drainage; this may be due to the fact thatasperinhabits waterways that do not drain into the Mississippi River. Perhaps intergradation is more prevalent than the morphological basis that I have relied upon indicates; in any event, there are few specimens that have more than one dark marginal line (which is the only character that is unique forasper) from the lower Mississippi drainage. A young male (TU 11928.9) from Bayou Gauche between Paradis and Des Allemands, St. Charles Parish, Louisiana, has a pattern on the carapace resembling that ofasper; several other small softshells (TU) are available from the same locality but none shows more than one dark marginal line. Another specimen (USNM 95192), a young female from a barrow pit of the Big Black River (Mississippi River drainage), Madison County, Mississippi, resemblesasperin having more than one marginal ring. Of three large females from Moon Lake, an ox-bow of the Mississippi River in Coatopa County, Mississippi (AMNH 5285-86, 5289), only 5289 shows evidence of two marginal lines. USNM 73669 (Greenwood, LeFlore County, Mississippi) also indicates intergradation in that the spots tend to be linear just inside the dark marginal[508]line, but the specimen more closely resembles thehartwegi-spinifercomplex rather thanasper.

There seems to be little adumbration of the dark marginal lines ofasperin populations from the lower Mississippi River drainage. Blackish spots and ocelli vary in size and there are many kinds of pattern on the carapace. Soft-shelled turtles inhabiting the Mississippi River and its tributaries in Louisiana and Mississippi certainly represent an intergrading population ofspiniferandhartwegi, and, to a lesser extent, ofasper. Soft-shelled turtles inhabiting the Pearl River drainage and rivers that drain into Lake Pontchartrain immediately adjacent to the east are predominantlyasper.

Specimens having localities from the Pearl River and Lake Pontchartrain drainages are listed under the account ofasperand are referred to that subspecies on the distribution map; specimens from the Mississippi drainage in Mississippi are referred tospinifer.

One specimen (UMMZ 59198, Bradley County, Tennessee), from the Tennessee River drainage whereT. s. spiniferoccurs, deviates markedly fromspiniferand suggests intergradation. UMMZ 59198, plastral length 4.8 centimeters, has ocelli in the center of the carapace only two millimeters in diameter, a distinct but interrupted, second marginal ring consisting of spots, and the pale postlabial and postocular stripes in contact on both sides of the head.

Specimens examined.—Total 110, as follows:Alabama:Barbour: UMMZ 113038, Chattahoochee River, Eufala.Cherokee: ANSP 24592, "near" center of Terrapin Creek.Conecuh: UMMZ 70736, Murder Creek, Castleberry.Escambia: TU 15823, Escambia River, 1 mi. N Sardine; UMMZ 70734, Escambia River at Flomaton.Henry: TU 15630, 3 mi. NW jct. Echo Farm Rd. and Rt. 136 on Echo Farm Rd.Lowndes: UMMZ 67759, Pintlalla Creek.Mobile: MCZ 1608 (2), 1608A, Mobile.Sumpter: USNM 83996, 3 mi. SE Coatopa.Tuscaloosa: TU 14673 (5), Black Warrior River, 17.5 mi. SSW Tuscaloosa; UA 52-1085, Cottondale.Walker: KU 50843, 50851, TU 17137, Mulberry Fork, Black Warrior River, 9 mi. E Jasper.

Florida:Calhoun: KU 50837-38, Chipola River, 4 mi. N Scott's Ferry; TU 16689 (4), Chipola River "near" Blountstown.Escambia: TU 13474, 15869 (3), 16584, Escambia River, 1.2 mi. E Century.Okaloosa: TU 15661, Blackwater River, 4.3 mi. NW Baker on Route 4.Santa Rosa: AMNH 44621, Blackwater River, Milton.Walton: UMMZ 110421, Pond Creek, 4 mi. SW Florala, Covington County, Alabama.

Georgia:Baker: TU 15889 (3), USNM 134243-48, Flint River "near" Newton; USNM 30822.Baldwin: USNM 8708, Milledgeville.Bryan: TU 15090, Canouche River, 2.3 mi. W Groveland.Chatham: USNM 51981, 92583-84, Savannah.Chattooga: UMMZ 113037, tributary of Chattooga River, Lyerly.Decatur: KU 50839-42, Flint River, 1.5 mi. S Bainbridge.Fulton: UMMZ 53037, Roswell.Lincoln: USNM 91282-83, above Price Island, Savannah River.Murray: UMMZ 59196, 9 mi. N Spring Place.Pulaski: TU 14882, Ocmulgee River, 4.3 mi. SE Hawkinsville.Richmond: USNM 66859, Augusta.Whitfield: UMMZ 74209, Cohulla Creek, Prater's Mill "near" Dalton.County unknown: MCZ 37172; UMMZ 109864, Flint River at mouth of Dry Creek; USNM 029034.

Louisiana:East Baton Rouge: LSU 11, 1643-44, City Park Lake in Baton Rouge; TU 17237, Amite River "near" Baton Rouge.St. Tammany: TU 6356, headwater creek of Bayou Lacombe; TU 16071, USNM 66147, mouth of Tchefuncta Creek in Lake Pontchartrain.Tangipahoa: TU 13623, 3.1 mi. W Hammond; USNM 68054, Robert.Washington: KU 50840, 50846, TU 17117, Pearl River at Varnado.Parish unknown(East Baton Rouge or Tangipahoa): UMMZ 95614, Manchac.

[509]

Mississippi:Chickasaw: USNM 115981, Chookatonkchie Creek.Clarke: USNM 79350-51, 1 mi. W Melvin, Choctaw County, Alabama; USNM 100805, Enterprise.Forrest: WEB 55-586, 1 mi. S Hattiesburg.Hancock: AMNH 46780; WEB 54-651, Hickory Creek "near" Kiln.Lauderdale: UMMZ 74681, 9 mi. W Meridian; UMMZ 90130, Lake Juanita, 15 mi. W Meridian.Lawrence: KU 47120, TU 17307.1, Pearl River, 9 mi. S Monticello; USNM 7653-54, Pearl River at Monticello.Lee: CM 31904, Verona; USNM 115979, Cower's Area near Guntown.Madison: USNM 95191, 95193-94, Pearl River.Marion: MCZ 1597, Pearl River at Columbus (designated type locality).Pearl River: CM 21100, Pearl River, 20 mi. W Poplarville; TU 14362, Hobolochito Creek, 1 mi. N Picayune.Perry: WEB 55-580, Beaver Dam Creek, 1 mi. N Richton.Walthall: KU 50844, Bogue Chitto River, Dillon.

South Carolina:Abbeville: USNM 7650, Abbeville? (reported by Pickens, 1927:113; locality considered in error by Stejneger, 1944:50; USNM 7650 having only one dark marginal line paralleling rear margin of carapace is possibly an aberrant specimen—see page 495 of present account).Greenwood: USNM 71681, 73668, Greenwood.McCormick: USNM 91310-12, Savannah River, 5 mi. W Plum Branch; USNM 92521, near Parksville.Richland: AMNH 70724-25, Broad River, Columbia.

No Data: USNM 8359 (erroneously reported from Madison, Indiana by Yarrow, 1882:29 and Hay, 1892:145; see discussion by Cahn, 1937:200, and Stejneger, 1944:73-75); USNM 131859.

Records in the literature.—Alabama:Coffee: Elba (KKA).Marengo: Tombigbee River near Demopolis.Mobile: Fig Island (Löding, 1922:47).

Florida:Jackson: Chattahoochee River, 8 mi. SE Butler.Leon: Ochlocknee River, NW of Tallahassee (Goin, 1948:304).

Georgia:Bartow: Etowah River below Allatoona Dam,ca.4 mi. ESE Cartersville (Crenshaw and Hopkins, 1955:15).Berrien: (Knepton, 1956:324).Emanuel: Ogeeche River (Schwartz, 1956:19).Fulton: Nancy Creek, Atlanta (Dunston, 1960:278).Gwinnett:Irwin: (Knepton,loc. cit.).Jenkins: Ogeeche River near Buckland Creek jct., 2.5 mi. S Millen.Liberty: Camp Stewart, 4 mi. N Hinesville.Morgan: Lake Rutledge (Schwartz,loc. cit.).Muscogee: Columbus (Stejneger, 1944:52).Wayne: Altamaha River, 5 mi. N Mt. Pleasant (Schwartz,loc. cit.).Wilcox: Ocmulgee River, 3-4 mi. SSE Abbeville (Crenshaw and Hopkins,op cit.:16, footnote; Schwartz,loc. cit.).

Mississippi:George: Whiskey Creek (Cook, 1946:185).Harrison: near Biloxi.Jackson: Pascagoula Swamp,ca.40 mi. E. Biloxi (Corrington, 1927:101).Jones: Eastabuchie.Lee: Cain Creek Bottom.Lincoln: Old Brook Creek.Lowndes: Tombigbee River, Camp Henry Pratt and Columbus; Lake Park, Columbus.Pearl River: 21 mi. SW Poplarville; 10 mi. W Poplarville; 4 mi. W Poplarville.Wayne: Trigg Area (Cook,loc. cit.).

North Carolina:Mecklenburg: Catawba River near Charlotte (Schwartz, 1956:20).

South Carolina:Aiken: Savannah River, 10 mi. SW Jackson.Allendale: Savannah River, Fennell Hill, 2 mi. S US 301.Anderson: Pendleton.Bamberg: South Edisto River, Cannon's Bridge, 5 mi. from Bamberg.Berkeley: 2.5 mi. W Pinopolis.Charleston: Charleston.Clarendon: Upper Lake Marion at US 301; Lake Marion, 13 mi. SW Manning; 3.3 mi. S Jordan; 6.3 mi. S Jordan; Wyboo Creek, 8.5 mi. from Manning.Colleton: Edisto River (Schwartz, 1956:19-20).Darlington: Pee Dee River, Society Hill (Stejneger, 1944:72).Dorchester: Edisto River, 17 mi. from Summerville; Edisto River, 14 mi. W Summerville; Edisto River, 2.5 mi. S Hart's Bluff.Fairfield: 1 mi. N Peak, Newberry County.Georgetown: North Santee River, 1 mi. above US 17.McCormick: Little River near McCormick; Little River, 3 mi. NE Mt. Carmel.Laurens: Enoree River, 3 mi. S Cashville, Spartanburg County; Enoree River, 9.4 mi. N Clinton.Orangeburg: Edisto River, Orangeburg.Saluda: Batesburg; Lake Murray; Little Saluda River; 5 mi. from Saluda.County unknown: Upper Lake Santee (Schwartz,loc. cit.).

Trionyx spinifer emoryi(Agassiz)Texas Spiny Softshell

Plates43,44

Aspidonectes emoryiAgassiz (in part), Contr. Nat. Hist. United States, Vol. 1, Pt. 2, p. 407; Vol. 2, Pt. 3, pl. 6, figs. 4-5, 1857.

T[rionyx] s[pinifer] emoryiSchwartz, Charleston Mus. Leaflet, No. 26, p. 11, 1956.

Back to IndexNext