Fes. 1912. MamMats oF ILLINOIS AND WISCONSIN — Cory. 239 
Family GEOMYID#. Pocket Gophers. 
The Geomyide are a family of fossorial or burrowing Rodents com- 
monly known as Pocket Gophers, which are restricted, so far as known, 
to North and Central America. They are characterized by the greatly 
developed claws of the fore feet, small eyes and ears and external 
cheek pouches lined with fur, which open on the sides of the face. 
Nine genera, three of which occur in the United States, and more than 
100 species and subspecies are recognized, but only one genus and a 
single species occur within our limits. 
Genus GEOMYS Rafinesque. 
Geomys Rafinesque, Amer. Monthly Mag., II, 1817, p. 45. Type 
Geomys pinetis Rafinesque. 
Upper incisors with two grooves (bisul- 
cate), a deep one in the middle and much 
smaller and narrower one near the inner 
edge; first and second upper molars with 
posterior enamel plate; infraorbital foramen 
confined to lower portion of maxilla; auditory 
meatus much elongated and tubular, opening 
Front view showing cheek between the mastoid process of the squamosal 
eee and posterior root of zygoma*; crowns of 
cheek teeth with transverse enamel loops, 
a single loop on each molar and two on the premolar; claws of fore 
feet much elongated; external cheek pouches large, opening on sides 
of face; eyes small; tail thick, much shorter than the body, and the 
terminal portion scantily haired; ears very small. 
I-I o-0 I-1t - 
, M. 3-3 3.56. 
T= 
Dental formula: I. . : 
o-o0 I-I 3=3 
Geomys bursarius (SHAW). 
Pocket GOPHER. 
Mus bursarius SHaw, Trans. Linn. Soc. Lond., V, 1800, p. 227. 
Geomys ? bursarius RICHARDSON, Fauna Bor. Amer., I, 1829, p. 203. 
Geomys bursarius LAPHAM, Trans. Wis. State Agr. Soc., II, 1852 (1853), p. 340 (Wis- 
consin). Kennicott, Trans. Ill. State Agr. Soc., I, 1853-54 (1855), p. 580 
(Cook Co., Illinois). Jb., Agr. Rept. for 1857, U. S. Patent Office Rept., 1858, 
*See Illustration, p. 96. 
