ON NOUTH AMERICAN ZOOLOGY. 15/ 



Saccomi/s anthop/tihis of F. Cuvier lias the teeth oi geomys, 

 but he has phiced it in a separate genus on account of the sup- 

 posed pecuHarity of its pendent pouches ; it is smaller than any 

 geomi/s we have seen, and differs from all that we have enu- 

 merated in the greater length of its tail. The cricetus fasciatns 

 of Rafinesque from Kentucky is probably either a geomys or 

 saccomys ; but if so, it is peculiar in having ten transverse 

 black streaks on the back, if indeed this appearance was not 

 pi'oduced, as is sometimes the case, by cracks in mounting the 

 skin. Apkiodontia leporina inhabits New Caledonia and the 

 banks of the Columbia, where its skins are used for clothing, 

 and form an article of traffic. 



The beaver ranges on the eastern side of the continent, from 

 the most northern woods down to the confluence of the Ohio 

 with the Mississippi ; and it would appear, from a remark of 

 Dr. Coulter's, that on the western side it descends in the 

 neighbourhood of the Tule lakes to the 3Sth parallel. The pur- 

 pose served in the economy of the animal by the castoreum 

 and a fatty substance deposited in the adjoining sacs has not 

 yet been made out. The Canada porcupine {erethizon clorsa- 

 tum) inhabits the country lying between the 37th and 67th 

 parallels. The hoitzlacuatzin of Mexico is identified by Lich- 

 tenstein with the synetheres prehensilis* , we do not know 

 with what propriety ; but if he be correct, it is, if not a solitary 

 instance, at least very nearly so, of a rodent animal being com- 

 mon to North and South America. The spotted cavy {coelo- 

 genys) and perhaps a species of cavia and one of dasyprocta ex- 

 tend from South America to the West Indies and Mexico ; but 

 in other respects the animals of this numerous order differ 

 greatly in the zoological provinces of North and South America. 

 The most northern American hare is lejms glacialis, which 



thinl}' clothed with very short whitish hairs. The incisors are differently 

 grooved in different species. Geomys hulbivorus and timhrimis have these 

 teeth quite smooth ; borealis and talpoides have a very fine groove close to the 

 inner margin of each upper incisor ; Douglasii has fine submarginal grooves 

 on all the incisors, viz., next to the inner edges of the upper ones and the 

 outer edges of the under ones ; buisarius and Drummondu have a deep rounded 

 furrow in the middle of the anterior surface of the upper incisors, in addition 

 to the fine inner submarginal one. The under incisors are quite plain in 

 Drummondii, and most likely in bursar'ms, also, as no mention is made of their 

 being grooved. In all these species the auditory opening is scarcely percep- 

 tibly elevated. Geoviys or ascomijs mexicanus of Licbtenstein has short 

 round ears, with a single central furrow in the upper incisors. A variety of 

 this is mentioned in Fischer's synopsis. Tliey are inhabitants of the Mexican 

 uplands, where they lay waste the maize-fields. 



• The island of Cuba nourishes another kind of rodent animal with a prehen- 

 sile tail, named caprovuja. 



