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1 GEOMYID45-GEOMY3 BUKSAllIUS. 0J3 



Ilamster du Canada, Desm., I. c 



PneudoHtome a bonne, Lkh8., I, c. 



DiploKtome hrmi, 1). blanche, Dehm., Lkss., (/. co. 



Canadian flamtter, GliIKK., 1. c. 



Qoffer, TuHchenmans, ScilINZ, I. c. •' 



PoHclied Hat, Sand Rat, Camat Hat, Pnckut Gopher, Snhnandrr, Viil^o. 



Uon/noT Gauffrt, French (wUorice EngliHh " ({"plier ", and Ot>riiiiiii "gnffer")- 



Diagnosis. — Superior incisors bisulcatc, with a fine siiiu|) groove along t lie 

 inner margin, and another, much larger, i)isccting the remiiining plane sur- 

 iiifc. Check-pouches ample, extending to the sliou!d(!rs. 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 &.hQ to 9.00 at least ; tail, 2 or 3 inches ; fore 

 foo', including longest fore claw, about IJ inches; iiiiid foot, including claw, 

 about \\ inches; longest fore claw, about 0.75 inch, but very variable — from 

 little over 0.50 to 1.25. 



Habitat -•'^alley of the Mississippi and its tributaries in a broad sense, 

 and somewhiit beyond to the northward. "Canada." Not known to occur in the 

 United States west of the Kocky 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 Kocky 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 hh-pulus, 

 such is probably the normal case in this genus; though in species of T/wmo- 

 mys I have distinctly recognized six pairs. 



The character of the infclsors 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. Tiie 

 other is a much larger, more profound, and wider sulcu.':, which fairly bisects 

 the remaining surface, leaving an equal plane area on either side, exclusive 

 of the small portion v.ut ofT by the fine marginal groove. This main groove 

 viries a good deal in depth and width in different specimens, and, moreover, 

 is itself sometimes sulcate ; that is to say, this excavati.,n iomrtimes presents. 





e i. 



