RODENTIA. 303 



forms being constantly discovered, several additions 

 have been made and others proposed ; but, as we 

 have neither in all cases the means of furnishing the 

 characters, nor space left in our volume, and as 

 most of them obtain but a very secondary attention 

 from readers, who are not decidedly attached to the 

 study of Mammalogy, and, moreover, as several 

 species, such as squirrels, hares, rats, and mice, have 

 already obtained a partial review in the Seventh 

 Volume of this Work, where the British Quadrupeds 

 are described, we shall pass over them in rapid 

 notice, dwelling, as on former occasions, only with 

 more detail on a few of the most interesting. Iii 

 the 58 genera, which, however, do not include Cte- 

 nodactylus, Helamys, Otomys of Dr. Smith, Akodon 

 of Meyen ; Heteromys of Desmarets, and Scccomys 

 of Fred. Cuvier ; there are, nevertheless, enumera- 

 ted by Mr. Waterhouse, 380 species ! So that this 

 order alone will be found to exceed 400, or more 

 than nearly double the number mentioned in Grif- 

 fith's Cuvier, published in 1827, for his Synopsis 

 contains only 180.* 



* We have to notice here the genus Cheiromys, one of those 

 forms in nature which baffle systematists in lineal classifi- 

 cation, but nevertheless represent the Rodents among Qua- 

 drumana^ or the Qadrumanous among Rodentia. "We think 

 now, that, among the Quadrumana, it should follow imme- 

 diately after Tarsius, although the dentition offers, as in Ro- 

 dents, incis. f , can. , m. |-| = 18 : fore legs short, hinder legs 

 long ; tail long, brushy, and the teats, two in number, are in- 

 guinal ; but the fore hands are each provided with very long 



