CYNOMYS. 153 



only too happy to be rid of their unwelcome neighbors had they the 

 power to cause their removal. These animals seem to be independent 

 of water, possibly the dew that often falls heavily in the districts in 

 which they live satisfying their moderate needs. Prairie-dogs are 

 not easily caught, and when captured, are difficult to tame, the wild, 

 free life of the plains, causing by comparison, that of a captive 

 to be unsupportable. They live on seeds and grasses, and their 

 cheek pouches are small. 



3 7 . Cyiiomys. 



Cynomys Rafin., Amer. Month. Mag., n, 1817, p. 45. Type Arctomys 

 litdoricianns Ord. 



Anisonyx Rafin., Am. Month. Mag., n, 1817, p. 45. (nee Latreille, 

 1807, Coleopt.) 



Lipura Illig., Prodr. Syst. Mamm., et. Av., 1811, p. 95. 



Monax Warden, Statist. Polit. Hist. Ace. U. S., i, 1819, pp. 

 225-228. 



Cheek pouches shallow; ears rudimentary; tail very short, flat; 

 feet with claws on all five toes; pollex large, nail well developed; 

 pelage short, bristly; dentition very heavy: molars large with three 

 transverse grooves on their crowns ; first and second premolars nearly 

 equal in size; outline of molar series curved, divergent anteriorly, 

 approximating posteriorly; postorbital processes strong, well devel- 

 oped, decurved; antorbital foramina large, subtri angular, the tubercle 

 at end large and visible when viewed frcm above, and projecting 

 beyond the superior outline of skull; palate greatly contracted pos- 

 teriorly; occipital and saggital crests present. 



KEY TO THE SPECIES. 



A. Size large. Check pouches present, shallow; 

 palate greatly contracted posteriorly; post- 

 orbital processes long, pointed. 

 a. Tail short, flat; pelage bristly. 



a/ Under parts white; tail with subterminal PAGE 



bar of broccoli brown .................. C. arizonensis 154 



b.' Under parts yellowish white; tail with 



apical third black .................... C. ludovicianus 155 



c/ Under parts pale fulvous ; tail with apical 



half mixed black and white ............. C. gunnisoni 156 



d/ Under parts buffy; tail with apical half 



black ................................ C. mexicanus 156 



