Chapter 7

Type.—Male, adult, no. 76562, Museum of Vertebrate Zoology, University of California; 1 mi. E Samalayuca, 4500 ft., Chihuahua, Mexico; obtained on May 15, 1937, by William B. Richardson, original no. 2148.

Range.—Known only from the type locality.

Diagnosis.—Size medium (see measurements). Color pale, entire dorsal surface Pinkish Buff, purest on sides and flanks, dorsal surface but slightly suffused with black; pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail light-brownish. Skull medium in size; nasals long; rostrum relatively as well as actually wide; least interorbital breadth wide; auditory bullae relatively little inflated; braincase but slightly vaulted; external auditory meatus ovoid; zygomatic arches relatively robust and but slightly bowed laterad; pterygoid fossae subcircular; lacrimal processes small; foramen magnum deeply notched on dorsal border.

Comparisons.—FromDipodomys ordii ordii,D. o. extractusdiffers as follows: Size larger; color lighter; arietiform marks absent inD. o. extractusbut pronounced inD. o. ordii; skull larger; rostrum wider; nasals longer; maxillary arches wider; auditory bullae more inflated laterally; braincase less vaulted; pterygoid fossae subcircular as opposed to circular; foramen magnum more deeply evaginated dorsally and ventrally.

Fig. 25.

Fig. 25.Known occurrences and probable geographic range of the subspecies ofDipodomys ordiiin the northeastern fourth of the range of the species.1.D. o. richardsoni8.D. o. terrosus18.D. o. montanus2.D. o. oklahomae10.D. o. uintensis24.D. o. priscus5.D. o. evexus11.D. o. sanrafaeli31.D. o. longipes6.D. o. medius15.D. o. luteolus33.D. o. nexilis

FromDipodomys ordii obscurus,D. o. extractusdiffers as follows: Size larger; color lighter; skull larger in all respects, notably in least interorbital width, greatest length of skull and breadth across auditory bullae; zygomatic arches less robust and straight as opposed to robust and bowed laterally; pterygoid fossae subcircular as opposed to circular; auditory bullae more inflated ventrally.

FromDipodomys ordii idoneus,D. o. extractusdiffers in: Size larger; color lighter; skull larger in all measurements taken except least interorbital width and breadth across maxillary arches which are smaller; nasals longer and narrower; braincase less vaulted; zygomatic arches less robust and more nearly straight; auditory bullae less inflated ventrally.

Remarks.—This subspecies ofDipodomys ordiiis the palest of any of the known races from Mexico. It inhabits an area of light-colored sandy soil at the type locality.

The only subspecies with whichD. o. extractusreally needs comparison isDipodomys ordii ordiifrom which it differs as described above. The series which is herein described contains two individuals that resembleD. o. ordiicranially and three that resemble it in color although they are somewhat paler. One specimen, MVZ no. 76560, is the palest of any of the series, has a short tail and in these respects resembles the pale form ofDipodomys ordii compactus. It is apparent from the skull of this latter individual that it is notD. o. compactusbutD. o. extractus.

Dipodomys ordii ordiiinhabits, in most of its range, dark-colored soils, whereasD. o. extractusinhabits light-colored soils. Possibly the differentiation that has occurred is a result of an ecological separation much as occurs withPerognathuson the white sands and black lavas of the Tularosa Basin of New Mexico (seeBenson, 1933).

Specimens examined.—Total, 14, all from Chihuahua, as follows: 1 mi. E Samalayuca, 4500 ft., 14 (MVZ).

Dipodomys chapmaniMearns, Bull. Amer. Mus. Nat. Hist., 2:291, February 21, 1890.

Cricetodipus chapmani, Trouessart, Catalogus Mammalium, 1:581, 1897.

Perodipus chapmani, Elliot, Field Columbian Museum, Zool. Ser., 2:237, 1901.

Perodipus ordii chapmani,Goldman, Proc. Biol. Soc. Washington, 30:113, May 23, 1917.

Dipodomys ordii chapmani,Grinnell, Journ. Mamm., 2:96, May 2, 1921.

Cotypes.—Male, no. 2400, and female, no. 2398, Amer. Mus. Nat. Hist.; Fort Verde, Yavapai County, Arizona; obtained on January 26, 1887, and 49October 1, 1885, respectively, by Edgar A. Mearns. (Type not seen.)

Range.—Central Arizona from the Grand Canyon of the Colorado River, southeastward to, and probably beyond, Fort Verde; marginal occurrences are: lower end Prespect Valley, Kirkland, Prescott, Camp Verde, Bill Williams Mountain.

Diagnosis.—Size medium (see measurements). Color dark; entire dorsal surface between (10") Pinkish Cinnamon and Cinnamon-Buff, purest on sides and flanks, upper parts strongly suffused with black; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, blackish. Skull medium in size; rostrum long and narrow; nasals long; auditory bullae slightly distended; braincase vaulted.

Comparisons.—For comparisons withDipodomys ordii cupidineus,Dipodomys ordii longipesandDipodomys ordii ordiisee accounts of those subspecies.

Remarks.—This subspecies ofDipodomys ordiiis relatively isolated from other subspecies of the species. The Colorado River with its deep canyons is interposed between the ranges ofD. o. chapmaniandD. o. cupidineus. A high range of mountains separatesD. o. chapmanifrom the range ofD. o. longipes. The only race with whichD. o. chapmaniprobably comes into contact isD. o. ordiito the southeast. No specimens are available from the southeastern part of the range ofD. o. chapmani. Animals from the northwestern part of the range ofD. o. ordii, without exception, have dark-colored pelage which is characteristic ofD. o. chapmani. In the shape of the nasals, vault of the braincase, interorbital width and auditory bullae, animals from Rice, Arizona, resembleD. o. chapmani, but in other characters resembleD. o. ordiito which subspecies they are referred. Animals from 20 miles northeast of Calva, Arizona, are dark-colored and are intermediate between the darkD. o. chapmaniand the paleD. o. ordiiin size of the cranium and body but are referable toD. o. ordii. In the northwestern part of the range ofD. o. chapmanithe animals are not typical in that they have a shorter, wider rostrum and a heavier zygomatic arch than topotypes.

Specimens examined.—Total, 90, all from Arizona, distributed as follows:Mohave County: lower end Prospect Valley, 4500 ft., Grand Canyon, 7 (USBS); Kingman, 9 (LACM).Coconino County: Aubrey Valley, 10 mi. S Pine Spring, 4 (USBS); Bill Williams Mountain, 1 (USNM).Yavapai County: 3 mi. N Fort Whipple, 11 (USBS); Fort Whipple, 4 (2 USBS; 2 USNM); Willow Creek, 4 mi. N Prescott, 4 (MVZ); 1 mi. W Camp Verde, 1 (MVZ); Camp Verde, 33 (15 USBS; 3 MVZ; 3 AMNH; 9 LACM; 3 DRD); 1/2 mi. S Camp Verde, 4 (MVZ); Kirkland, 9 (USBS); Turkey Creek, 3 (USBS).

Dipodomys montanusBaird, Proc. Acad. Nat. Sci. Philadelphia, 7:334, April, 1855.

Perodipus montanus, Merriam, Proc. Biol. Soc. Washington, 17:140, July 14, 1904.

Perodipus ordii montanus,Goldman, Proc. Biol. Soc. Washington, 30:113, May 23, 1917.

Dipodomys ordii montanus,Grinnell, Journ. Mamm., 2:96, May 2, 1921.

Type.—Male, no. 490/1631, U. S. Nat. Mus.; near Fort Massachusetts, Costilla County, Colorado; obtained in 1853 by F. Kreutzfeldt (Pacific Railroad Survey).

Range.—The San Luis Valley of south-central Colorado and north-central New Mexico; marginal occurrence are: in Colorado, 22 mi. E Mosca, Saguache, Alamosa and Antonito; in New Mexico, 4 mi. SW Cimmaron.

Diagnosis.—Size small (see measurements). Color dark, entire dorsal surface between (c) Vinaceous-Buff and Avellaneous, purest on sides and flanks, upper parts strongly suffused with black; arietiform markings, pinnae of ears, plantar surfaces of hind feet and dorsal and ventral stripes of tail, blackish. Skull small; rostrum slender; interorbital width narrow; auditory bullae strongly inflated; braincase but slightly vaulted; interparietal region wide; zygomatic arch bowed laterally.

Comparisons.—FromDipodomys ordii richardsoni,D. o. montanusdiffers as follows: Size smaller; color darker in all pigmented areas; ventral stripe of tail continuous to end of pencil in all specimens, whereas inD. o. richardsonithe stripe is incomplete in most specimens. In all specimens the dorsal and ventral stripes of the tail are darker inD. o. montanus; skull smaller in all measurements taken; jugal straight or nearly so, as contrasted to bowed laterally; pterygoid fossae shallower and more ovoid, that is to say, wings of pterygoid flare laterally; ventral projection of auditory bullae more pronounced; rostrum, immediately in front of zygomatic process of maxilla, nearly parallel to median plane along long axis of skull, while inD. o. richardsonithis union forms a decided obtuse angle; paroccipital processes smaller; foramen magnum smaller and more ovoid as opposed to larger and more circular.

FromDipodomys ordii evexus,D. o. montanusdiffers as follows: Size smaller in all measurements taken except width across auditory bullae which is greater; color darker, ventral stripe of tail continuous to end of pencil; least width of supraoccipital less (2.5 mm. inD. o. montanusand 3.5 mm. inD. o. evexus); extension of premaxillae posterior to nasals greater; braincase more inflated dorsally; bullae relatively as well as actually larger and more inflated ventrally; pterygoid fossae narrower anteroposteriorly and wider laterally than inD. o. evexus; jugal straight or nearly so as contrasted to bowed laterally; lacrimal processes smaller.

For comparison withDipodomys ordii mediussee account of that subspecies.

Fig. 26.

Fig. 26.Known occurrences and probable geographic range of the subspecies ofDipodomys ordiiin the southwestern fourth of the range of the species.14.D. o. ordii17.D. o. chapmani31.D. o. longipes

Remarks.—This subspecies ofDipodomys ordiiappears to be restricted to the San Luis Valley of Colorado and New Mexico. Intergradation, betweenDipodomys ordii ordiiandD. o. montanus, is noted in animals from Gran Quivira, Mesa Jumanes, New Mexico. These animals have the frontomaxillary suture and extension of the premaxilla as inD. o. ordiiand the nasals and inflation of the auditory bullae as inD. o. montanus. In the majority of characters they are, however, referable to the latter. Intergradation is noted also in animals from 4 miles southwest of Cimmaron, New Mexico, in that they resembleD. o. richardsoniin the shape of the nasals and the width and length of the rostrum but in the remainder of the characters studied resembleD. o. montanusto which they are referred.

Baird, in the original description, gives "near Fort Massachusetts" as the type locality for this subspecies.Miller(1923) lists the type locality as "Fort Massachusetts (now Fort Garland)." Fort Massachusetts and Fort Garland are two different ex-army posts. Old Fort Massachusetts was situated on what is now the Trinchera Ranch which is north of the town of Fort Garland. Old Fort Garland is approximately one-half mile south of the town of Fort Garland. The two abandoned army posts were no more than twelve miles apart. In 1946, at neither abandoned post could I find any habitat suitable for kangaroo rats.

Specimens examined.—Total, 148, distributed as follows:

Colorado:Saguache County: Saguache, 1 (USBS).Alamosa County: 1.6 mi. NE Medano Springs Ranch Headquarters, 8 (MVZ); Great Sand Dunes National Monument, 10 (MVZ); 8 mi. S Great Sand Dunes National Monument, 4 (MVZ); Medano Ranch, 15 mi. NE Mosca, 11 (2 USBS; 9 MVZ); 22 mi. E Mosca, 5 (AMNH); Alamosa, 1 (UM).Conejos County: Antonito, 1 (USBS); 7 mi. E Antonito, 3 (USBS); 12 mi. E Antonito, 2 (USBS).Costilla County: 4-1/2 mi. N Blanca, 8100 ft., 3 (MVZ); 1 mi. NE Blanca, 7950 ft., 1 (MVZ); 3 mi. NW Fort Garland, 6 (CMNH); 1 mi. NW Fort Garland, 3 (MVZ); 15 mi. W Fort Garland, 7800 ft., 4 (KU); Fort Garland, 64 (31 USBS; 28 LACM; 5 MVZ); 5 mi. SSE Fort Garland, 4 (AMNH); 5 mi. S Fort Garland, 2 (AMNH).

New Mexico:Colfax County: 4 mi. SW Cimmaron, 5 (AMNH); 3 mi. SE Cimmaron, 8 (AMNH); 1-1/2 mi. W Philmont Ranch Headquarters, 2 (AMNH).

Dipodomys ordii cinderensisHardy, Proc. Biol. Soc. Washington, 57:53, October 31, 1944.

Type.—Male, no. 4611, Mus. Zool., Univ. Utah; at approximately 4,000 ft. on sandy soil, immediately north of the northern of two large cinder cones in Diamond Valley, 10 mi. N St. George, Washington County, Utah; obtained on February 13, 1944, by Ross Hardy, original no. 2690.

Range.—Diamond Valley, Washington County, Utah, north through Mountain Meadows, east as far as Cedar City, Iron County, Utah, north through the Escalante Desert to Lund, Iron County, and west almost to the Utah-Nevada boundary; marginal occurrences, all in Utah are: 11 mi. SE Lund; N end Mountain Meadows; Diamond Valley; 10 mi. W Cedar City; 4-1/2 mi. NW Summit and 6 mi. W Parowan.

Diagnosis.—Size small (see measurements). Color dark, upper parts near Buffy Brown, strongly suffused with black, purest on sides and flanks; pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, arietiform markings, black. Skull small; rostrum narrow; auditory bullae relatively as well as actually well inflated; external auditory meatus small; interparietal region narrow.

Comparisons.—FromDipodomys ordii fetosus,D. o. cinderensisdiffers in: Size smaller; color darker; skull smaller in all measurements taken.

FromDipodomys ordii panguitchensis,D. o. cinderensisdiffers as follows: Size smaller; color lighter; skull smaller except for auditory bullae which are larger; external auditory meatus smaller; maxillary tooth-row longer.

Compared withDipodomys ordii longipesandDipodomys ordii cupidineus,D. o. cinderensisis smaller, darker and can easily be distinguished.

For comparisons withDipodomys ordii celeripesandDipodomys ordii utahensissee accounts of those subspecies.

Remarks.—This race confined to Utah, and inhabiting northern Washington County and most of Iron County, is restricted almost exclusively to areas of loose shifting sand. Intergradation withDipodomys ordii fetosusoccurs near Lund. The animals from this locality intergrade in size of body and in color, but in the majority of cranial characters resembleD. o. cinderensis. In all characters studiedD. o. cinderensisappears to be more closely related toDipodomys ordii utahensisthan to any other subspecies with which it comes into actual contact.

Animals from near Parowan have both cranial and external characters by which they could be referred to eitherD. o. panguitchensisorD. o. cinderensis. Owing to the existence of the physical barrier (Cedar Mountains) separating the two populations, they are referred toD. o. cinderensis.Dipodomys ordii cinderensisis not a well differentiated race but appears to possess characters sufficiently diagnostic to distinguish it from contiguous forms.

Specimens examined.—Total, 74, all from Utah, distributed as follows:Iron County: 11 mi. SE Lund, 50 (46 RH; 4 MVZ); 4-1/2 mi. NW Summit and 6 mi. W Parowan, 9 (RH); 10 mi. W Cedar City, 1 (USAC); 5 mi. W Cedar City, 1 (USAC); Cedar City, 2 (BYU).Washington County: Diamond Valley, 9 (RH); N end Mountain Meadows, 2 (RH).

Dipodomys ordii fetosusDurrantandHall, Mammalia, 3:14, March, 1939.

Type.—Female, adult, no. 48451, Museum of Vertebrate Zoology, University of California; 2 mi. N Panaca, 4,800 ft., Lincoln County, Nevada; obtained on June 24, 1931, by Ward C. Russell, original no. 1658.

Range.—Southeastern Nevada and western Beaver and Millard counties, Utah; marginal occurrences in Nevada, 2 mi. SE Pioche, 15 mi. WSW Sunnyside, 16-1/2 mi. WSW Sunnyside, 14 mi. NNE Sharp, 8-1/2 mi. NE Sharp, 15 mi. S Groom Baldy, 10 mi. E Crystal Spring, Panaca; in Utah, Pine Valley, 50 mi. W Milford and 5 mi. S Garrison.

Diagnosis.—Size medium (see measurements). Color dark, entire dorsal surface (16") between Pinkish Cinnamon and Cinnamon-Buff, purest on sides and flanks with strong admixture of black in upper parts; cheeks white; pinnae of ears, arietiform markings, plantar surfaces of hind feet, dorsal and ventral stripes of tail, blackish. Skull medium in size; rostrum wide and short; interorbital region narrow; braincase but slightly vaulted; lacrimal processes large; zygomatic arches weak and bowed laterally; pterygoid fossae large and subcircular.

Comparisons.—FromDipodomys ordii utahensis,D. o. fetosusdiffers as follows: Hind foot longer; color lighter; skull larger; rostrum, relatively as well as actually, shorter and wider; nasals longer and wider; interorbital region narrower; braincase less vaulted; interparietal region narrower; auditory bullae more inflated laterally, posteriorly and ventrally; foramen magnum smaller.

FromDipodomys ordii celeripes,D. o. fetosusdiffers as follows: Larger; color darker; arietiform markings present; skull larger; rostrum longer and wider; nasals longer and less inflated distally; interorbital region wider; auditory bullae somewhat more inflated; zygomatic arches more robust.

For comparisons withDipodomys ordii monoensis,D. o. columbianus,D. o. pallidus,D. o. panguitchensisandD. o. cinderensissee accounts of those subspecies.

Remarks.—Dipodomys ordii fetosushas a small geographic range.Hall(1946:416) points out that the interorbital breadth in topotypes is less than in those from any other part of the range. This feature, therefore, is not useful in characterizing this subspecies. Intergradation withDipodomys ordii columbianusis noted in the greater total length and the somewhat darker color in animals from Coal Valley and Garden Valley, Nevada. In the part of the range which lies in Utah, none of the animals is typical and all are intergrades in color and cranial characters withDipodomys ordii celeripes.

Specimens examined.—Total, 136, distributed as follows:

Nevada:Nye County: White River Valley, 15 mi. WSW Sunnyside, 5500 ft., 26 (MVZ); White River Valley, 16-1/2 mi. WSW Sunnyside, 5500 ft., 6 (MVZ); 14 mi. NNE Sharp, 1 (MVZ); Garden Valley, 15 mi. NE Sharp, 1 (MVZ); Garden Valley, 14-1/2 mi. NE Sharp, 3 (MVZ); 8-1/2 mi. NE Sharp, 17 (MVZ).Lincoln County: E side Coal Valley, 14 mi. N Seeman Pass, 4850 ft., 4 (MVZ); 2 mi. SE Pioche, 1 (MVZ); E side Coal Valley, 10 mi. N Seeman Pass, 1 (MVZ); Desert Valley, 20 mi. SW Pioche, 1 (MVZ); 2 mi. N Panaca, 4800 ft., 17 (16 MVZ; 1 CAS); Desert Valley, 21 mi. W Panaca, 10 (MVZ); Crystal Spring, Pahranagat Valley, 4000 ft., 2 (MVZ); 10 mi. E Crystal Springs, 5000 ft., 1 (MVZ); 15 mi. S Groom Baldy, 1 (MVZ).

Utah:Millard County: 5 mi. S Garrison, 5400 ft., 12 (MVZ); Pine Valley, Sec. 33, T. 25 S, R. 17 W, 5000 ft., 16 (UU); Warm Cove, Sec. 34, T. 25 S, R. 18 W, 5500 ft., 2 (UU); Desert Range Experiment Station, 50 mi. W Milford, 5252 ft., 10 (9 UU; 1 BYU).

Perodipus montanus utahensisMerriam, Proc. Biol. Soc. Washington, 17:143, July 14, 1904.

Perodipus ordii utahensis,Goldman, Proc. Biol. Soc. Washington, 30:113, May 23, 1917.

Dipodomys ordii columbianus,Grinnell, Journ. Mamm., 2:96, May 2, 1921.

Dipodomys ordii columbianus,Hall, Univ. California Publ. Zool., 37:5, April 10, 1931 (part—the part from Ogden, Utah.)

Type.—Male, adult, no. 55115, U. S. Nat. Mus. Biol. Surv. Coll.; Ogden, Weber County, Utah; obtained on July 15, 1893, by VernonBailey, original no. 4085.

Range.—Between Great Salt Lake and the Wasatch Mountains from extreme northern Utah, south to northern Sevier County, Utah; marginal occurrences, all in Utah, are: Promontory Point, Ogden, St. John, Cedar Valley, Nephi, Aurora, Spring City, Provo and 4 mi. N Draper.

Diagnosis.—Size small (see measurements). Color dark, entire dorsal surface (a) between Cinnamon-Buff and Clay Color, purest on sides, flanks and cheeks, with heavy admixture of black in upper parts; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail blackish. Skull small; rostrum short and narrow; interorbital region moderately wide; interparietal large, spatulate anteriorly; lacrimal processes relatively large; braincase vaulted; zygomatic arches robust and straight; auditory bullae relatively, as well as actually, greatly inflated.

Comparisons.—FromDipodomys ordii marshalli,D. o. utahensisdiffers as follows: Size smaller; color darker; skull smaller; rostrum longer and narrower; interorbital region wider; lacrimal processes larger; interparietal region larger; auditory bullae less inflated; palate longer and narrower.

FromDipodomys ordii pallidus,D. o. utahensisdiffers in: Size smaller; color darker; skull smaller; rostrum shorter and narrower; interorbital region narrower; auditory bullae less inflated laterally, posteriorly and ventrally; interparietal region larger; lacrimal processes smaller; foramen magnum with ventral notch as opposed to rounded ventrally; pterygoid fossae circular as opposed to subcircular; palate longer and narrower.

FromDipodomys ordii cinderensis,D. o. utahensisdiffers as follows: Size larger, except hind foot which is shorter; color somewhat lighter, more reddish; skull larger; rostrum longer; nasals longer; braincase more vaulted; pterygoid fossae circular as opposed to subcircular; auditory bullae less inflated laterally but more inflated ventrally.

For comparisons withDipodomys ordii columbianus,D. o. fetosus,D. o. marshalli,D. o. panguitchensisandD. o. cineraceussee accounts of those subspecies.

Remarks.—The systematic status ofD. o. utahensishas long been in doubt. Several workers have, at various times, considered it to be indistinguishable fromDipodomys ordii columbianus.Durrant and Setzer(1945:29) recognized it as a valid subspecies and gave diagnostic characters by which it could be distinguished fromD. o. columbianus.

Intergradation has been noted in specimens from the eastern and southeastern shores of Great Salt Lake. In color and the width of the auditory bullae these specimens are intermediate betweenD. o. utahensisandDipodomys ordii marshallibut in the sum total of characters are referable to the latter. Specimens from 20 miles southwest of Nephi and from U. B. (Yuba) Dam are darker and intermediate in rostral width and breadth of the auditory bullae but are referable toDipodomys ordii celeripes.

Specimens examined.—Total, 91, all from Utah, distributed as follows:Box Elder County: Promontory Point, 1 (USNM).Weber County: Ogden, 4293 ft., 20 (7 BYU; 7 MVZ; 4 USNM); Little Mountain, 1 (USNM).Davis County: Antelope Island, Great Salt Lake, 4250 ft., 5 (USNM).Tooele County: Bauer, 4500 ft., 6 (UU); St. John, 4300 ft., 4 (UU); Little Valley, Sheeprock Mountains, 5500 ft., 1 (UU); Clover Creek, Onaqui Mountains, 5500 ft., 1 (UU).Salt Lake County: Plain, 4 mi. N Draper, 4500 ft., 1 (UU).Utah County: Fairfield, Cedar Valley, 4800 ft., 15 (9 BYU; 6 UU); W Lake Mountains, 9 (BYU); Provo, 4510 ft., 10 (MVZ); Sand Dunes W Curtis Station, 4 (BYU).Juab County: Nephi, 2 (1 USNM; 1 MVZ); 4 mi. W Nephi, 1 (RH).San Pete County: Spring City, 4 (LACM).Sevier County: 1 mi. W Aurora, 5190 ft., 6 (5 UU; 1 USNM).

Perodipus ordi columbianusMerriam, Proc. Biol. Soc. Washington, 9:115, June 21, 1894.

Dipodomys phillipii, Baird, U. S. P. R. R. Expl. and Surveys, Gen. Rept., p. 412, 1857 (part—the part from Ft. Walla Walla, O. T.).

Cricetodipus ordii columbianus, Trouessart, Catalogus Mammalium, 1:581, 1897.

Perodipus ordii columbianus,Goldman, Proc. Biol. Soc. Washington, 30:113, May 23, 1917.

Dipodomys ordii columbianus,Grinnell, Journ. Mamm., 2:96, May 2, 1921.

Type.—Female, adult, no. 24181/31594, U. S. Nat. Mus., Dept. of Agriculture, Coll.; Umatilla, Plains of Columbia, Umatilla County, Oregon; obtained on October 18, 1890, by Clark P. Streator, original no. 386.

Range.—Southeastern Washington, eastern Oregon, southwestern Idaho, northwestern, northern and most of northeastern Nevada; marginal occurrences are: in Washington, 2 mi. SW Paterson, 4 mi. E Burbank and Wallula; in Oregon, 7 mi. E Madras, 2 mi. E Prineville and Guano Valley; in California, Eagleville, Red Rock, Observation Peak, 5 mi. E Litchfield, Honey Lake, Vinton; in Nevada, 3-1/2 mi. E Flanigan, 6 mi. S Pahrum Peak, 2-1/2 mi. E and 11 mi. N Gerlach, 2 mi. SW Quinn River Crossing, 1 mi. SE Tuscarora, 5 mi. N Beowawe, 1/2 mi. S Beowawe, 2-1/2 mi. NE Smiths Creek Ranch, Bells Ranch, 5 mi. W Austin, 8 mi. W Eureka, 4 mi. S Shoshone, 5 mi. SE Greens Ranch, and 22 mi. N Deeth; in Idaho, 8 mi. W Rodgerson, 6 mi. SW American Falls, 4 mi. NE American Falls, 5 mi. NW Michaud, Arco, Hammett and Payette; in Oregon, Umatilla.

Diagnosis.—Size medium (see measurements). Color dark, entire dorsal surface (16") between Pinkish Cinnamon and Cinnamon-Buff, purest on sides and flanks with strong admixture of black on upper parts; cheeks white; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, blackish. Skull medium in size; rostrum relativelylong and narrow; nasals long and expanded distally; interorbital region narrow; lacrimal processes small; braincase but slightly vaulted; auditory bullae relatively greatly inflated; pterygoid fossae circular; zygomatic arches robust.

Comparisons.—FromDipodomys ordii utahensis,D. o. columbianusdiffers as follows: Color lighter, dorsal and ventral stripes of tail brownish as opposed to black; ventral stripe of tail, in most specimens, incomplete to end of pencil as opposed to complete; lacrimal processes smaller; extension of premaxillae dorsad wider; interparietal generally narrower, smaller, quadrangular and truncate anteriorly, as opposed to spatulate and rounded anteriorly; braincase less vaulted; zygomatic arches bowed laterally as opposed to straight; styloid processes larger; cutting edge of upper incisors narrower.

FromDipodomys ordii fetosus,D. o. columbianusdiffers in: Hind foot shorter; color generally darker; skull larger; rostrum shorter and wider; nasals somewhat shorter; braincase more vaulted; auditory bullae less inflated; interparietal region wider; ventral border of foramen magnum more rounded (less indented); zygomatic arches straight as opposed to bowed laterally.

For comparisons withDipodomys ordii inaquosus,Dipodomys ordii monoensisandDipodomys ordii celeripessee accounts of those subspecies.

Remarks.—In most subspecies ofDipodomys ordiihaving large geographic ranges, there is a certain amount of variation, butD. o. columbianusremains relatively stable throughout its large range. Where extreme variation is noted inD. o. columbianusit is obviously the result of intergradation. This intergradation is noted betweenDipodomys ordii monoensisandD. o. columbianusin Lyon County, Nevada, where the animals are referable to the former race cranially but to the latter on the basis of color. Animals from Kelton, Utah, are in color asDipodomys ordii marshalliand cranially combine characters ofD. o. columbianus,D. o. utahensisandD. o. marshalli. The sum total of their characters places them withD. o. marshalli.Durrant and Setzer(1945:29), and the present writer in this account, do not record any animals from Utah as belonging toD. o. columbianus. Nevertheless, the influence ofD. o. columbianusis seen in the animals from Kelton, Utah.

Specimens examined.—Total, 588, distributed as follows:

Washington:Benton County: Blalock Island, 2 mi. SW Paterson, 2 (MVZ).Walla Walla County: 4 mi. E Burbank, 4 (MVZ); 2 mi. SSE Burbank, 27 (MVZ); Wallula, 7 (4 MVZ; 3 DRD).

Oregon:Gilliam County: Arlington, 1 (MVZ). Morrow County: 2-1/2 mi. SW Irigon, 6 (MVZ); Cecil, 1 (MVZ).Umatilla County: Umatilla, 10 (MVZ).Jefferson County: 7 mi. E Madras, 2 (DRD).Crook County: 2 mi. NE Prineville, 1 (MVZ); 7 mi. W Prineville, 8 (MVZ); 4 mi. SW Prineville, 23 (MVZ); Crooked River, at mouth of Bear Creek, 8 (MVZ).Lake County: Fort Rock, 1 (DRD); NE edge Alkali Lake, 8 (MVZ); 9 mi. S Adel, mouth 20 Mile Creek, 1 (MVZ); Guano Ranch, Guano Valley, 2 (DRD).Harney County: Malheur Lake, 9 (LACM); Narrows, 1 (DRD); 1 mi. S Narrows, 3 (MVZ); 5 mi. SW Narrows, 19 (MVZ); Smith Creek, 10 mi. SE Diamond, 1 (MVZ); Lake Alvord, 1 (MVZ); 1-1/2 mi. E Denio, 4 (MVZ).Malheur County: 3 mi. N Vale, 2 (MVZ); 8 mi. N Jordan Valley, 1 (MVZ); 1/2 mi. S Rome, 5 (MVZ); 1 mi. S Rome, 11 (MVZ).

Idaho:Payette County: Payette, 1 (DRD).Butte County: Arco, 1 (MVZ).Elmore County: Hammett, 1 (MVZ).Bingham County: 5 mi. E Shelley, 1 (MVZ); Blackfoot, 5 (MVZ); 3 mi. S Blackfoot, 6 (MVZ); Aberdeen, 1 (MVZ).Owyhee County: S bank Snake River, Homedale, 13 (MVZ); Indian Cove, 4 (MVZ); 5 mi. SE Murphy, 3 (MVZ); Castle Creek, 8 mi. S Oreana, 1 (MVZ); S Fork Owyhee River, 12 mi. N Nevada line, 1 (MVZ).Minidoka County: Acequia, 8 (MVZ); 4 mi. N Rupert, 2 (MVZ).Twin Falls County: Salmon Creek, 8 mi. W Rodgerson, 7 (MVZ).Power County: 5 mi. NW Michaud, 4 (MVZ); 4 mi. NE American Falls, 4 (MVZ); 6 mi. SW American Falls, 10 (MVZ).

California:Modoc County: Eagleville, 12 (CAS); 2 mi. E Eagleville, 7 (CAS); 2-1/2 mi. E Eagleville, 24 (CAS); 3 mi. E Eagleville, 6 (CAS); 5 mi. E Eagleville, 3 (CAS).Lassen County: 2 mi. W Red Rock P. O., 1 (MVZ); 1 mi. W Red Rock P. O., 4 (MVZ); Dransfield, 6 mi. E Ravendale, 5300 ft., 4 (CAS); 7 mi. E Ravendale, 1 (MVZ); 7 mi. N Observation Peak, 21 (MVZ); 6 mi. N Observation Peak, 7 (MVZ); Observation Peak, 31 (MVZ); Pete's Valley, 4 (MVZ); 5 mi. E Litchfield, 12 (MVZ); 6 mi. W Wendell, 3975 ft., 3 (CAS); 8 mi. SW Wendell, 5 (CAS); Honey Lake, 2 (LACM); 4-1/2 mi. WNW Stacy, 5 (MVZ); 3 mi. NW Warm Springs, 1 (MVZ).Plumas County: Beckwith, 1 (DRD); 2 mi. WNW Vinton, 2 (MVZ); Vinton, 18 (14 LACM; 4 MVZ); 1 mi. E Vinton, 7 (MVZ); near Vinton, 21 (DRD).

Nevada:Washoe County: 3 mi. N Vya, 3 (MVZ); 4-1/2 mi. NE Painted Point, 4 (MVZ); 8-1/2 mi. E Vya, 1 (MVZ); 3 mi. E Painted Point, 1 (MVZ); Long Valley Ranch, 3 mi. S Vya, 1 (MVZ); 10-1/2 mi. S Vya, 1 (MVZ); 11 mi. S Vya, 2 (MVZ); 13 mi. S Vya, 4 (MVZ); Hausen, 4800 ft., 8 (MVZ); 10 mi. SE Hausen, 4675 ft., 7 (MVZ); 2-1/2 mi. E and 11 mi. N Gerlach, 4050 ft., 4 (MVZ); Smoke Creek, 9 mi. E California line, 3900 ft., 5 (MVZ); 40° 28' N Lat., 6 mi. E California line, 4000 ft., 3 (MVZ); Horse Canyon, 3 mi. NW Pahrum Peak, 5000 ft., 1 (MVZ); Fox Canyon, 6 mi. S Pahrum Peak, 4800 ft., 4 (MVZ); N side Sand Pass, 3950 ft., 2 (MVZ); 4 mi. NW Flanigan, 4200 ft., 1 (MVZ); 3-1/2 mi. NW Flanigan, 4200 ft., 1 (MVZ); 3-1/2 mi. E Flanigan, 2 (MVZ); 2-3/4 mi. SW Pyramid, 4300 ft., 2 (MVZ).Humboldt County: 1 mi. S Denio, Oregon, 4200 ft., 6 (MVZ); Quinn River Crossing, 4100 ft., 1 (MVZ).Elko County: Mary's River, 22 mi. N Deeth, 3 (MVZ); 1 mi. SE Tuscarora, 5900 ft., 2 (MVZ); 5 mi. W Halleck, 5200 ft., 7 (MVZ); 3 mi. W Halleck, 5300 ft., 2 (MVZ).Lander County: 1 mi. E Battle Mountain, 1 (MVZ); Reese River Valley, 6 mi. N Austin, 2 (MVZ); Malloy Ranch, 5 mi. W Austin, 3 (MVZ); 2-1/2 mi. NE Smiths Creek Ranch, 5800 ft., 1 (MVZ); Campbell Creek, 6900 ft., 3 (MVZ); Campbell Creek Ranch, 5500 ft., 8 (MVZ).Eureka County: 5 mi. N Beowawe, 7 (MVZ); 1/2 mi. S Beowawe, 1 (MVZ); Pine Creek, 2 mi. E Palisades, 7 (MVZ); Evans, 4 (MVZ); Winzell, 3 (MVZ); 4 mi. SE Romano, Diamond Valley, 1 (MVZ); 8 mi. W Eureka, 12 (MVZ).White Pine County: 5 mi. SE Greens Ranch, Steptoe Valley, 1 (MVZ); Cherry Creek, 6600 ft., 2 (MVZ); 1 mi. E Illipah, 6100 ft., 3 (MVZ); 5-1/2 mi. SE Ely, 6500 ft., 5 (MVZ); Spring Valley, 5900 ft., 4 mi. S Shoshone, 6 (MVZ).Nye County: Bells Ranch, Reese River, 6890 ft., 1 (MVZ).

Type.—Male, adult, no. 90029, Museum of Zoology, University of Michigan; San Juan, 12 mi. W Lerdo, 3,800 ft., Durango, Mexico; obtained on March 1, 1946, by F. and F. Hammerstrom.

Range.—Known only from the type locality.

Diagnosis.—Size small (see measurements). Color pale, entire dorsal surface (c) between Light Ochraceous-Buff and Ochraceous-Buff, purest on sides, flanks and cheeks; upper parts but slightly washed with black; arietiform markings, lateral parts of pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, brownish; medial part of pinnae of ears flesh-colored. Skull medium in size; rostrum wide and relatively long; braincase but slightly inflated; least interorbital width great; interparietal region relatively narrow; upper incisors strongly recurved; zygomatic arches relatively heavy and slightly bowed laterally; auditory bullae greatly inflated ventrally, laterally and posteriorly.

Comparisons.—FromDipodomys ordii ordii,D. o. idoneusdiffers in: Sizesmaller; color lighter; skull larger; nasals longer and somewhat more inflated distally as opposed to straight; interorbital width greater; breadth across maxillary arches greater; interparietal region narrower; auditory bullae more inflated posteriorly, laterally and ventrally and projecting anteriorly into orbit; extension of nasals anterior to upper incisors less; zygomatic arches heavier and more bowed laterally; paroccipital processes smaller; foramen magnum elongate as opposed to nearly circular.

FromDipodomys ordii obscurus,D. o. idoneusdiffers as follows: Size smaller; color lighter; skull larger, rostrum wider; nasals shorter and more expanded distally; interorbital region wider; width across maxillary arches greater; interparietal region narrower; auditory bullae more inflated laterally, posteriorly and ventrally; zygomatic arches shorter, heavier and less bowed laterally.

FromDipodomys ordii palmeri,D.o. idoneusdiffers in: Size smaller; color lighter; skull larger; rostrum shorter and wider; nasals shorter and more expanded distally; interorbital region wider; auditory bullae more inflated laterally, posteriorly and ventrally; zygomatic arches heavier.

FromDipodomys ordii fuscus,D. o. idoneusdiffers as follows: Size smaller; color lighter; skull smaller; rostrum narrower and shorter; interorbital width greater; braincase more vaulted; nasals longer; interparietal region generally wider; auditory bullae less inflated; breadth across maxillary arches greater; zygomatic arches heavier and more bowed laterally; pterygoid fossae ovoid as opposed to subcircular; occipital condyles more anterior to dorsal evagination when viewed ventrally.

Dipodomys ordii idoneusdiffers fromDipodomys ordii attenuatusin larger size, generally darker color and larger skull.

Remarks.—This subspecies ofDipodomys ordiiis paler than either of the subspecies with adjoining geographic ranges. Measurements of the skull, in proportion to external measurements, are larger than in any other subspecies ofDipodomys ordii. Cranially, this new subspecies is more closely allied toDipodomys ordii fuscusbut in color appears to be much closer toDipodomys ordii attenuatusfrom which it differs markedly in cranial features.

Specimens examined.—Total, 3, all from Durango, distributed as follows: San Juan, 12 mi. W Lerdo, 3 (UM).

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