1915.] 



TflOMOMYS TALPOIDES GEOUP. 



107 



large and rounded, widening base of skull and narrowing shaft of 

 basioccipital; interparietal more or less triangular. 



Measurements. — Type ( c? ad.): Total length, 209; tail vertebrae, 

 60; hind foot, 28. Topotype ($ ad.): 208, 68, 27. Slull (of type): 

 Basal length, 34; nasals, 13; zygomatic breadth, 22.7; mastoid 

 breadth, 18.7; alveolar length of upper molar series, 8. 



Remarks. — The relationships of this form are doubtful. In many 

 respects it resembles the talpoides group, especially in arrangenient 

 of mammae and in general skull characters. In small ears and rather 

 square-built skull it seems close to quadratus, and there is some ques- 

 tion whether along the borders of its range it does not interbreed with 

 both quadratus ^TLdfuscus. Two young females from Asotin, Wash., 

 are probably typical of columhianus , but are too young to afford reliable 

 characters. An old male from Willows Junction, Oreg., is very small, 

 but is provisionally referred to columhianus. 



Specimens examined. — Total number, 37, as follows: 



Oregon: Pendleton, 4; Umatilla, 9; "Willows Junction, 1. 



Washington: Asotin, 2; Baird, 9; Fort Walla Walla, 3; Prescott, 4; Touchet, 4; 

 Wallula, 1. 



THOMOMYS OCIUS Merriam. 

 Green River Pocket Gopher. 



(PI. II, fig. 12; PI. VII, fig. 9.) 



TJiomomys clusius ocius ^lerriam, Proc. Biol. Soc. Washington, XIV, 114, July 19, 

 1901. 



Type. — Collected near Old Fort Bridger, Wyoming (exact locality, 

 dry sagebrush mesas at Harvey's Ranch, on Smiths Fork, 6 miles 

 southwest of Fort Bridger), by Vernon Bailey, May 24, 1890. Type 

 specimen in U. S. Nat. Mus., Biological Survey collection. 



Distrihution, — Green River Basin of southwestern Wyoming, north- 

 western Colorado, and northeastern Utah (fig. 10). 



Characters. — Size small; color very pale; skull slender, with very 

 large and rounded audital bullae and sharply incurved upper incisors ; 

 ears very small but pointed; mammse normally in 7 pairs, inguinal 

 2-2, abdominal 2-2, pectoral 3-3. 



Color. — Summer pelage: Upperparts light buffy gray, more strongly 

 buffy or tinged with brownish on crown and back:; sides clear gray; 

 cheeks darker gray; ear patch blackish but small; underparts, feet, 

 and tail soiled whitish or creamy. Winter pelage: Upperparts lighter 

 buffy gray; nose and cheeks clearer gray; underparts whitish or 

 creamy. 



Skull. — Rather narrow, with slightly arched dorsal outline; inter- 

 parietal short and wide; temporal ridges slightly converging ante- 

 riorly; posterior tips of nasals rounded; audital bullae very large and 



