1915.] 



THOMOMYS TALPOIDES GEOUP. 



97 



Ascomys horealis Wagner, Suppl. Sclireber Saug., Ill, 391, 1843. Taken from 

 Richardson. 



Geomys unisulcatus Gray, List Mamm. Brit. Mus., 149, 1843. Nomen nudum. 

 Saccophorus horealis Gray, List Mamm. Brit. I\Ius., 149, 1843. From Richardson. 

 Ascomys talpoides^YsLgner, SuppL Schreber Saug., Ill, 390, 1843. From Richardson. 

 Ascomys horealis "Wagner, SuppL Schreber Saug., Ill, 391, 1843. From Richardson. 

 Pseudostoma talpoides Audubon & Bachman, Quad. N. Am., Ill, 43-45, 1854; de- 

 scribed and figured from type specimen in collection Zool. Soc, London. 

 Geomys (Thomomys) talpoides Giebel, Saug., 530, 1855. Compiled from Richardson. 

 Thomomys talpoides Baird, Mamm. N. Am., 403, 1857. 



Type} — Type locality fixed at near Fort Carlton (Carlton House) on 

 the Saskatchewan River, Saskatchewan. Type specimen in British 

 Museum, a stuffed skin and anterior part of skull, which was removed 

 from the skin in 1893. 



Distribution. — Plains of Saskatchewan and Alberta; south in 

 Montana to Great Falls and the Big Snowy Mountains (fig. 10). 



Characters, — Size medium, between that of rufescens and clusius; 

 ears prominent and pointed; claws slender; color dull and dark 

 gray; skidl not heavily ridged and with sUght temporal ridges often 

 converging anteriorly or in the middle; nasals emarginate posteriorly; 

 rostrum slender; mammae normally in 6 pairs, inguinal 2-2, 

 abdominal 2-2, pectoral 2-2. 



Color. — Summer pelage: Upperparts dull grayish brown with 

 plumbeous nose and blackish ear patch; underparts buffy or soiled 

 whitish gray; chin, and often throat and breast, pure white; feet 

 whitish; tail white tipped or sometimes all white. Winter pelage: 

 Upperparts dull dark gray, with httle brownish; ear patch black; 

 underparts washed with whitish. 



STcuTl. — Rather short and wide, with anteriorly converging tem- 

 poral ridges in all but very old individuals; nasals emarginate at 

 posterior tips or rarely truncate; interparietal triangular; audita! 

 bullse full and wide but low, with anterior arm of basioccipital narrow 

 between them. Dentition noticeably lighter than in rufescens; upper 

 incisors abruptly decurved and distinctly grooved. 



Measurements. — Largest male from Borden, Saskatchewan: Total 

 length, 214; tail vertebrae, 60; hind foot, 28. Largest female from 

 same place: 210,60, 29. Skull ( c? ad. from Borden, Saskatchewan): 

 Basal length, 34.5; nasals, 14; zygomatic breadth, 23; mastoid 

 breadth, 19; interorbital breadth, 6; alveolar length of upper molar 

 series, 7. 



1 The type of talpoides, a stuffed skin with part of skull, was procured from Mr. Leadbeater, a London 

 dealer, and was recorded from "Hudson Bay." This evidently meant the country of the Hudson's Bay 

 Co., or western Canada. There are no gophers known nearer the shores of Hudson Bay than on the 

 Saskatchewan, where, as Dr. Allen has pointed out, Richardson refers to them in his original description. 

 Carlton House or Fort Carlton, where Richardson remained for some time, and apparently the highest 

 point he reached on the Saskatchewan River, is near the easternmost point at which these gophers are 

 kno\vTi to occur along the river. As other species are found farther west on the Saskatchewan, it is neces- 

 sary to restrict the type locaUty of talpoides still further to the vicinity of Carlton House. 

 98121°— 15 7 



