144 Merriam — Three New Rodents from Colorado. 



black above and sharply tricolor as in albigula; feet white as in albigula. 

 Skull peculiar. 



Cranial characters. — Skull, compared with albigula, shorter and 

 broader; rostrum much more swollen laterally; nasals broader and more 

 squarely truncate anteriorly, longer (along median line) than frontal (in 

 albigula subequal with frontal); frontal shorter; frontomaxillary suture 

 (at anterior root of zygoma) straight (in albigula angular); zygomata 

 heavier and somewhat more spreading; bullae smaller and more rounded; 

 molars heavier (broader). 



Measurements. — Type specimen, male: Total length, 324; tail vertebra?, 

 137 ; hind foot, 36. An adult female from type locality: Total length, 

 330; tail, 14<>; hind foot, :;4. 



Thomomys talpoides agrestis subsp. now 



Type from Medano Ranch, San Luis Valley, Colorado. No. 150,725 

 U. S. National Museum, Biological Survey Collection. 9 ad. Collected 

 October 29, 1*>07, by Merritt Cary. Original No. 1205. 



Characters. — Size and general characters much as in talpoides but color 

 very different — pale drab as in ocius instead of dark brown as in talpoides; 

 skull also different. 



Color. — Upperparts uniform drab, sometimes with a pale reddish (dull 

 ochraceous) cast on top of head and neck; ear spots conspicuously dusky ; 

 underparts soiled whitish, the plumbeous underfur showing through. 



Cranial characters. — Skull similar to that of talpoides but averaging 

 longer and narrower; zygomata less spreading; nasals less regular, less 

 truncate posteriorly, less straight on outer side — tending to spread out- 

 ward on posterior third ; premaxillse longer and broader posteriorly; 

 maxillary root of zygomata longer and broader and swollen to articula- 

 tion with jugal so that the jugal part of arch is abruptly and conspicuously 

 narrower; bullae slightly more swollen. 



Measurements. — Type: Total length, 220; tail vertebra?, 57; hind foot, 

 30. Average of 4 females from type locality: Total length, 212; tail 

 vertebra 3 , 55; hind foot, 29. 



