Descriptions of Eight New Pocket Gophers. 215 



Color. Upper parts from half way between eyes and nose posteriorly to 

 tail, russet fulvous; under parts dark plumbeous, washed with salmon 

 fulvous ; nose, muzzle all round, and ear spot dusky ; fore and hind feet 

 and tail whitish, irregularly clouded with dusky. 



Cranial characters. Skull short and broad; zygomata abruptly and 

 widely spreading, with anterior-external angle nearly square and jugals 

 parallel; nasals rather short, broad, squarely truncate posteriorly, and 

 early ankylosed together; temporal ridges distant, parallel; interparietal 

 rather large and roughly oval ; audital bullse rather large; upper incisors 

 not sloping forward. 



Measurements. Type specimen: total length, 220; tail vertebrse, 67; 

 hind foot, 29. Average of 6 specimens from type locality: total length, 

 205; tail vertebrae, 64; hind foot, 27. 



Thomomys leucodon sp. nov. 



Type from Grant Pass, Rogue River Valley, Oregon. No. ff gf f, cT ad. 

 U. S. Nat. Mus., Biological Survey Coll. Collected Dec. 17, 1891, by C. 

 P. Streator. Original No. 1394. 



General characters. Similar to T. laticeps from Humboldt Bay, but 

 smaller ; under parts brighter fulvous ; incisors white instead of yellow 

 and sloping more strongly forward ; all the teeth much smaller. 



Color. Upper parts from nose to tail dull fulvous brown, becoming 

 brighter on sides and belly ; nose, sides of mouth, and ear spots dusky 

 [no dusky ring round eye]; fore and hind feet whitish; tail yellowish 

 buff. 



Cranial and dental characters. Braincase broad ; zygomata widely spread 

 ing; temporal ridges parallel, distant; interparietal rather large, shield 

 shaped ; skull similar to that of T. laticeps but smaller ; nasals narrower 

 and more deeply notched posteriorly ; basi-occipital narrower ; incisors 

 sloping far forward, their anterior faces white (sometimes slightly stained 

 with pale yellow), narrower and more rounded than in laticeps. 



Measurements. Type specimen: total length, 221; tail vertebrae, 68 ; 

 hind foot, 29. 



Thomomys operarius sp. nov. 



Type from Keeler, Owens Lake, Inyo Co., California. No. lig, tf ad. 

 U. S. Nat. Mus., Biological Survey Coll. Collected Nov. 29, 1890, by 

 E. W. Nelson. Original No. 1. 



General characters. Size small; color pale buffy ; fore claws very long 

 and slender ; cranial characters peculiar. Does not require comparison 

 with any known species. 



Color. Uniform buffy yellowish or buff gray (according to pelage) from 

 end of nose to tail ; post-auricular spots plumbeous ; under parts plum 

 beous strongly washed with white ; fore and hind feet and tail white. 



Cranial characters. Skull short, broad, and massive, with widely and 

 squarely spreading zygomata, short and broad rostrum, broad interorbital 

 region, and well marked temporal ridges (1-2 mm. apart in adults). 



