CANADA POUCHED RAT. 333 



SYNONYMES. 

 Mus BuKSARius, Shaw, Descript. of the M. Bursarius in Linn. Transact., vol. t., p. 



227 to 228. 

 Mns Bursarius, Shaw's Gen. Zool., vol. ii., p. 100, pi. 138, (figures with cheek-pouches 



unnaturally inverted.) 

 Mus Bursarius, Mitchill, Silliman's Journal, vol. iv., p. 183. 

 Mus Saccatus, Mitchill, N. Y. Medical Repository, Jan. 1821. 

 Saccophorus Bursarius, Kuhl, Beit., p. 66. 

 Cricetus Bursarius, Desm. in Nouv. Diet., 14, p. 177. 



" " F. Cuv. in Diet, des Sc. Nat., t. XX, p. 257. 



PsEUDOSTOMA BuRSAEiDS, Say, in Long's Expedi., vol. i., p. 406. 

 " " Godm., vol. ii., p. 90, fig. 2. 



" " Harlan, p. 133. 



Geomys % Bursarius, Rich., F. B. A., p. 203. 



DESCRIPTION. 



Head, large ; nose, broad and obtuse, covered with hair, with the ex- 

 ception of the margins of the nostrils, which are naked ; the nostrils are 

 small oblong openings a line apart, and are on their superior margins 

 considerably vaulted. 



The incisors protrude beyond the lips ; they are very large and trun- 

 cated ; in the superior jaw they are each marked by a deep longitudinal 

 groove near the middle, and by a smaller one at the inner margin : in 

 the young, they exhibit only a single groove. The molars penetrate to 

 the base of their respective alveoles without any division into roots, their 

 cro\vns are simply discoidal, transversely oblong-oval, margined by the 

 enamel ; the posterior tooth is rather more rounded than the others, and 

 that of the upper-jaw has a small prominent angle on its posterior face ; 

 the anterior tooth is double, in consequence of a profound duplicature in 

 its side, so that its crown presents two oval disks, of which, the anterior 

 one is smallest, and in the lower-jaw somewhat angulated. (Sat.) 



Eyes, small ; ears, very short, and scarcely visible ; whiskers, not 

 nimierous, shorter than the head. 



The cheek-pouches are very large, extending from the sides of the 

 mouth to the shoulders, and are internally lined with short soft hairs ; 

 the body is broad and stout, sub-cylindrical, and has a clumsy appear- 

 ance, not unlike that of the shrew-mole. It is thickly clothed on both 

 the upper and lower surfaces with soft hair, that on the back being in 

 some parts half an inch long, whilst on the under surface it is much 

 shorter, and more compact. 



The feet have five toes each ; the fore-feet are robust, with large, elon- 

 gated, compressed, and hooked nails ; the middle nail is much the 

 longest, the fourth is next in length, the second shorter, the fifth still 



