102 SPERMOPHILUS. CYNOMYS. 



Geogr. Distr. Valley of Saskatchewan, and through those of the 

 Red River and Mississippi, to the Dakotas and central Kansas. 

 Eastern limit western Indiana. 



Genl. Char. Size rather large; tail more than half the length of 

 head and body; ear very small. 



Color. Above yellowish brown spotted obscurely with black; 

 top and sides of head and neck, rump and thighs gray; beneath 

 whitish. Tail grayish white, with three black lines, outermost broad 

 and fringed with white. 



Measurements. Total length, 378; tail vertebra^, 139; hind foot, 52. 



39. Cyiioniys. 



I. Iizl; P. izl-^ M. 2=i = 22. 



Cynomys. Rafin. Month. Mag., 1817, ii, p. 45. Type .irctomys 

 ludovUianus. Ord. 



.Anisony.x, Rafin. Month. Mag., 1817, II, p. 45. 



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

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

 pelage short; dentition very heavy; molars large with three trans- 

 verse 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; anteorbital foramen large subtriangular, the tubercle 

 at end large and visible when viewed from above, and projecting be- 

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

 teriorly; occipital and saggital crests present. 



131. ludovicianus. {Arctomys), Ord., Guth. Geog., 1817, p. 292. 



socialis, Rafin. Am. Month. Mag., 1817, II, p. 45. 



grisea, Rafin. Am. Month. Mag., 1817, II, p. 45. 



missouriensis,V^3.iden, Descrip. Etats-Unis, v. 1820, p. 627. 



latrans, Harlan, Faun. Am., 1825, p. 306. 



Type locality. Plains of the Upper Missouri. 



Geogr. Distr. Western Texas to 49th parallel, and western Kan- 

 sas to eastern base of the Rocky Mountains. 



Genl. Char. Body stout; tail short; ears very small; claws long. 



Color. Summer Pelage. Above reddish brown, varied with gray 

 and black hairs; beneath yellowish white. Tail like the back with 

 the apical third black. 



Winter Pelage. Above pale vinaceous buff, grizzled and mixed 

 with black; below pale buff. 



Measurements. Total length, 393; tail vertebrae, 88; hind foot, 57. 



