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GENUS TAMIAS.— Illiger. 

 Incisive ^ ; Canine ^ ; Molar ^^ = 22. 



Upper incisors, smooth ; lower ones, compressed and sharp ; molars, 

 with short, tuberculous crowns. 



Nose, pointed ; lip, cloven ; ears, round, short, not tufted or fringed ; 

 cheek-pouches, ample. 



Tail, shorter than the body, hairy, sub-distichous, somewhat tapering. 

 Mammae, exposed ; feet, distinct, ambulatory ; fore-feet, foxir toed, with a 

 minute blunt nail in place of a thumb ; hind-feet five toed ; claws, hooked. 



This genus differs from Sciurus in several important particulars. The 

 various species that have been discovered, have all the same characteris- 

 tics, and strongly resemble each other in form, in their peculiar markings, 

 and in their habits. In form they difier from the true squirrels, and ap- 

 proach nearer to the spermophiles ; they have a sharp, convex, nose, 

 adapted to digging in the earth ; they have longer heads, and their ears 

 are placed farther back than those of the former. They have a more 

 slender body and shorter extremities. Their ears are rounded, without 

 any tufts on the borders or behind them. They have cheek-pouches, of 

 which all squirrels are destitute ; their tails are roundish, narrow, seldom 

 turned up, and only sub-distichous. 



The species belonging to this genus are of small size, and are all lon- 

 gitudinally striped on the back and sides. 



Their notes are very peculiar ; they emit a chipping clucking sound 

 differing very widely from the quacking chattering cry of the squirrels. 



They do not mount trees unless driven to them from necessity, but dig 

 burrows, and spend their nights and the season of winter under ground. 



They are, however, more closely related to the squirrels than to the sper- 

 mophiles. The third toe from the inner side is slightly the longest, as in 

 the former ; whilst in the latter, the second is longest, as in the mar- 

 mots. The genus Tamias is therefore nearly allied to the squirrels, whilst 

 the spermophiles approach the marmots. 



Authentic species of the genus Sciurus are already very numerous, and 

 as we have now a number of species, to which constant additions are 

 making by the explorers of our Western regions, which by their cheek- 

 pouches, their markings, and habits, can be advantageously separated 



