Vol. XXIII, pp. 79-80 May 4, 1910 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



X' 





TWO NEW POCKET GOPHERS OF THE GENUS 



THOMOMYS. 



BY VERNON BAILEY. 



A critical study of the genus Thowonnis shows two well marked 

 forms hitherto unnamed. One of these, from the yellow pine 

 plateaus of northern New Mexico, is large and dark; the other, 

 from the bottoms of hot desert l)asins of Avestern Nevada, is 

 large and pale. Both belong to the aureus group but mark its 

 opposite extremes. 



Thomomys apache sp. nov. 



Type from Lake La Jara (7,.3UU feet altitude), on tlie Jicarilla Apache 

 Indian Reservation, New Mexico. Nnmber 135,366, c? adult, U. S. 

 National Museum, Biological Survey Collection. Collected September 19, 

 1904, by James H. Gaut. Original number 3289. 



General characters. — Size large, hind foot 33-34; colors dark; hind feet 

 and tip of tail conspicuously white. 



Color. — Upper and lower parts nearly uniform dull, sooty gray, slightly 

 washed with dull Ijuffy ocliraceous; back with an ill-defined stripe of 

 blackish; basal half U) three-quarters of tail brownisli or l)lackish, the 

 rest abruptly white; hind feet white; lips usually and chin rarely white. 



Skull. — Heavy, angular and ridged, similar in form and general char- 

 acters to that of aureus; bullae full and rounded; pterygoids U-shaped; 

 nasals normally with slightly emarginate, doul:)ly rounded posterior tips; 

 iipper incisors white tipped and decurved at right angles to axis of skull. 



Measurements. — Type, total length, 250; tail vertebrfe, 85; hind foot, 

 34. Adult female topotype, 229; 74; 33. Skull of type, basal length, 41; 

 nasals, 14; zygomatic breadth, 28; mastoid breadth, 23; alveolar length 

 of upper molar series, 8.5. 



Thomomys canus sp. nov. 



Type from Deep Hole, at north end of Smoke Creek Desert, Nevada. 

 No. 78,365, c? adult, U. S. National ^Museum, Biological Survey Collec- 



IS— Pi;oc. Bkii.. Scic. Wash., V"I.. XXIII, 1910. (T'.D 



