CRATOGEOMYS. 



THOMOMYS. 



Fig. 51. Cratogeomys castanops. 



No. 4 Field Columbian Museum Coll. Nat. size. 



Gi-n/. Char. Size medium; tail medium. Skull: broad, heavy; 

 basioccipital rectangular, sides parallel; rostrum and brain case long; 

 superior profile convex; end of maxillary root of zygoma greatly 

 expanded, forming a plate. 



Color. Above yellowish brown mixed with black; beneath buffy, 

 base of hairs plumbeous, visible. Fore feet black, hind feet blackish 

 brown. Tail hairs blackish. 



Af,-tisiirrmrnfs-. Total length, 295; tail vertebras, 77; hind foot, 33. 

 Another specimen from Paladura Canon, Texas, measured in total 

 length, a8o; tail vertebrae, 80; hind foot, 39. Collector's measurement. 



I. 



60. Thomoniys. 



1=£; p. !=1; M. ?=-! = 



Thoitiomys. Max. Nov. Act. Akad. Caes. Leop., 1839, p. 383. Type 

 T. ru/iscins. Prinz Max. 

 Diplostoma, Rich., Faun. Bor. Amer., 1829, i, p. 206, (nee Rafin). 

 Oryctomys, Ed. & Gerv. Mag. Zool., 1836, p. 23 (Part). 



