GEOMYIDAi—GEOMYS BURSARIUS. 613 
Hamster du Canada, Drso., I. c. 
Pseudostome & bourse, LEss., l. c. 
Diplostome brun, D. blanche, DEsM., LEss., 11. ce. 
Canadian Hamster, Grirv., 1. ¢. 
Goffer, Taschenmaus, SCHINZ, I. c. 
Pouched Rat, Sand Rat, Camas Rat, Pocket Gopher, Salamander, VuuGo. 
Goufre or Gauffre, French (whence English “ gopher”, and German ‘‘ goffer”). 
Diacyosis.—Superior incisors bisulcate, with a fine sharp groove along the 
inner margin, and another, much larger, bisecting the remaining plane sur- 
face. Cheek-pouches ample, extending to the shoulders. Hands, including 
claws, longer than feet. Tail and feet hairy. Pelage soft, sleek, mole-like. 
Color dull reddish-brown, muddy-gray or hoary beneath, the basal portion of 
the fur plumbeous throughout (general color sometimes blackish-gray) ; feet 
and tail, for the most part, white or colorless. Average dimensions of adult, 
7 to 8 inches, but ranging from 6.50 to 9.60 at least; tail, 2 or 3 inches; fore 
foo‘, including longest fore claw, about 14 inches; hind foot, including claw, 
about 14 inches; longest fore claw, about 0.75 inch, but very variable—from 
little over 0.50 to 1.25. 
Hasirar—Valley of the Mississippi and its tributaries in a broad sense, 
and somewhat beyond to the northward. ‘Canada.” Not known to occur in the 
United States west of the Rocky Mountains. Specimens examined from the 
whole immediate valley of the Mississippi, from the State of that name to Min- 
nesota and Dakota; also from Texas; from the Platte, Washita, and Niobrara 
Rivers, &c.; and from the eastern foot-hills of the Rocky Mountains of Colorado. 
In the female, there are three pairs of teats—two inguinal, near together 
along the inside of the thighs; and another pair, pectoral, at a considerable 
distance. I have not been able to discover any more; and as the same num- 
ber and position have been found to hold in G. tuza, mexicanus, and hispidus, 
such is probably the normal case in this genus; though in species of Themo- 
mys | have distinctly recognized six pairs. 
The character of the incisors demands special notice, as it is diagnostic 
of the species. Two grooves upon each upper incisor always persist distinctly. 
One of these is a sharp, fine line of impression, running along the inner 
margin of the tooth, about the distance of its own width from the edge. The 
other is a much larger, more profound, and wider suleus, which fairly bisects 
the remaining surface, leaving an equal plane area on either side, exclusive 
of the small portion cut off by the fine marginal groove. This main groove 
varies a good deal in depth and width in different specimens, and, moreover, 
is itself sometimes sulcate ; that is to say, this excavation sometimes presents, 
