138 Proceedings of the Biological Society of Washington. 



smaller. Skull very like that of canus but zygomata less outstanding 

 anteriorly, braincase slightly less broad posteriorly, and toothrow a little 

 longer; bullae of same size. 



Measurements. — Average of <> specimens from type locality (Birch 

 Creek, Idaho): Total length, L82; tail, 37; hind foot, 29.5. Average of 5 

 from Blackfoot: 201, 43.5, :;'-\ 



Citellus mollus pessimus subsp. nov. 



Type from lower part of Big Lost River, east central Idaho. No. |f| ( ; 

 male adult, l T . S. Nat. Museum, Biol. Survey Coll. Collected July 23, 

 1890, by C. P. Streator. Original No. 53. 



Characters. — Similar to artemesiae (from Birch Creek) but somewhat 

 larger and darker ; tail longer, larger, and darker; rostrum larger. 



Cranial characters. — Skull small like that of artemesiae but longer; 

 rostrum and nasals longer and broader; tootln-ow longer. Compared with 

 mollis, skull smaller; bullae and teeth decidedly smaller. 



Measurements. — Average of 8 from type locality: Total length, 205; tail 

 vertebrae, 16; hind foot, 33. 



Citellus mollis washoensis subsp. nov. 



Tiijh from Carson Valley, western Nevada. Type No. '', ..'',, adult, D. S. 

 Nat. .Museum, Biol. Survey Coll. Collected May 23, 1889, by Charles A. 

 Keeler. Original No. 34. 



Characters. — Size large; coloration grizzled gray throughout, resem- 

 bling canus. Skull large, long, and massive — nearly as large as that of 

 idahoensis from Payette, Idaho, hut narrower, with more slender rostrum, 

 much more slender premaxillae, and shorter toothrow. Similar to mollis, 

 out more massive; rostrum and palate longer. Compared with largest 

 skulls of ceinus, the rostrum is much longer and more slender; superior 

 surface of premaxillae much slenderer; j^alate much longer; bullae 

 somewhat larger; toothrow decidedly longer. 



Measurements of type specimen: Total length, 258; tail vertebrae, 50; 

 hind foot, 35. 



