Family GEOMYIDAE 



151 



GEOMYS BURSARIUS (Shaw) 



Plains Pocket Gopher''' 



Description. — The plains pocket gopher, fig. 85, in Illinois 

 usually is slate gray to black on the back, light gray on the under 

 parts, and white on the nose, feet, and terminal half of the tail. 

 In other parts of its range, this gopher is principally brown or 

 taw^ny, but in Illinois only rarely is one found that is chocolate 

 brown on the back. The eyes are small, and the ears are round 

 and extremely short. The front legs are stout, and the claws of 

 the front feet are long. The tail is about one-third the length 



Fig. 85. — Plains pocket gopher. 



of the head plus body and sparsely covered with short hairs. An 

 external pocket or pouch is present on each side of the mouth. 

 The lips can be closed behind the long, heavy upper incisors. 



Length measurements: head and body of males 7^-8^ 

 inches (200-222 mm.), of females 7-8i4 inches (180-210 mm.) ; 

 tail 21/-4 inches (65-100 mm.) ; over-all for males 10i/-12^4 

 inches (265-322 mm.), for females 9Y2-\2]/^ inches (245-311 

 mm.) ; hind foot about 1^ inches (30-37 mm.). Weight: about 

 Ya pound (300-400 gm.). 



The skull is strongly ridged for muscle attachments and is 

 49-59 mm. (about 2Y% inches) long in males, 46-56 mm. (about 

 2 inches) in females. The rostrum is heavy and broad. The 

 incisors are strong, and each upper incisor has at least two 

 grooves on its front surface, fig. 73f. Dental formula: I 1/1, 

 C 0/0, Pm 1/1, M 3/3. 



*Not to be confused with the ground squirrels, sometimes called gophers. 



