108 Merriam N~ew Species of fhomomys. 



Thomomys sinalore sp. nov. 



Type from Altata, Sinaloa, Mexico. No. 00,745, $ axl., U. S. Na 

 tional Museum, Biological Survey Collection. March 28, 1899. E. A. 

 Goldman. Original No. 13,607. 



CJtaracte.ru. Size rather large; color dull pale chestnut brown. Re 

 lated to cerrinus from Phoenix, Arizona, but darker and with distinctive 

 cranial characters. 



Color. Upperparts dull pale chestnut brown, fading insensibly into 

 paler chestnut fulvous of underparts; region around mouth pale dusky, 

 not sharply contrasted with throat as in cerrinus. 



Cranial character*. Skull rather large and angular with strongly 

 spreading depressed and sJuirply angular zygomata. Similar in general to 

 cerriwtK but shorter; zygomata more broadly spreading, more depressed, 

 and with more prominent anterior angle: bulhe smaller. 



Mntx-itrrmr.nt*. Type specimen ( $ ad.): total length 233; tail verte 

 brae 73; hind foot 31. Average of G adults from type locality: total 

 length 221; tail vertebne 74; hind foot 31.5. 



Thomomys perditus sp. nov. 



Type from Lampazos, Nuevo Leon, Mexico. No. j'jH^i, $ ad., U. S. 

 National Museum. Biological Survey Collection. January 22, 1891. C. 

 P. Streator. Original No. 512. 



Character*. Si/e small; color drab gray; related to toltecus but small 

 er, grayer, and with distinctive skull characters. 



Color. Upperparts drab gray, strongly mixed with black-tipped hairs 

 and washed on sides with buffy (on sides of shoulders and rump becom 

 ing buffy fulvous); region around mouth dusky; underparts and fore 

 legs and feet buffy salmon; hind feet soiled whitish. 



Cranial characters. Skull small; bra-incase broadly swollen; zygomata 

 moderately spreading, the outer sides parallel; interparietal subquad- 

 rate; nasals cuneate, notched behind, and ending about on plane of pre- 

 maxilhe; bullye medium or rather small. Differs from toltecus in having 

 more cuneate nasals which are notched instead of truncate behind, and 

 which end about on plane of premaxillse instead of falling far short of 

 premaxillu 1 ; post zygomatic notch deeper and broader: upper incisors 

 more prominent. 



Measurements. Type specimen ( $ ad.): total length 195; tail verte 

 bne 59; hind foot 2(5.5. Average of 5 adults from type locality: total 

 length 185; tail vertebne 55; hind foot 25. 



Thomomys goldmani sp. nov. 



Type from Mapimi, Durango, Mexico. No. 58,075, $ ad., U. S. Na 

 tional Museum, Biological Survey Collection. December 15, 1893. E. 

 A. Goldman. Original No. 240. 



