RODENTIA. 101 



LAGOMYS, Cuv.(l) 



Moderate ears; legs nearly alike; the hole below the eye simple; clavicles 

 nearly perfect, and no tail; they often utter a sharp cry. They have hitherto 

 been found in Siberia only, and it is to Pallas that we are indebted for their 

 discovery. 



The fossil bones of an unknown species of Lagomys have been discovered 

 in the osseous breccia of Corsica. 



After the two genera of Porcupines and Hares, come the Rodentia, 

 united by Linnaeus and Pallas under the name of CAVIA; but to which it is 

 impossible to affix any other common and positive character than that of 

 their imperfect clavicles, although the species of which they are composed 

 are very analogous to each other, both in body and habits. They are all 

 from the western continent. 



HYDROCHCERUS, Erxleb.(2) 



Four toes before and three behind, all armed with large nails, and united 

 by membranes; four grinders throughout, of which the posterior are the 

 longest, and composed of numerous, simple and parallel laminae; the an- 

 terior laminae, forked towards the external edge in the upper, and towards 

 the internal one in the lower teeth. Only one species is known, the Capy- 

 bara, which inhabits Guiana. 



CAVIA, Illig. 



The Cobayes, or Guinea-Pigs, are miniature representations of the Cabiais; 

 but their toes are separated, and each of then* molars has only one simple 

 lamina, and one that is forked on the outside in the upper ones, and on the 

 inside in the lower. It is found in the woods of Brazil and Paraguay. 



CHLOROMYS, Fr. Cuv.(3) 



The Agoutis have four toes before and three behind; four grinders through- 

 out, almost equal, with flat crowns irregularly furrowed, rounded borders 

 notched on the internal edge in the upper jaw, and on the external one in 

 the lower. In disposition, and in the nature of their flesh, they resemble 

 Hares and Rabbits, which they may be said to replace in the Antilles and 

 hot parts of America. 



CCELOGENYS, Fr. Cuv.(4) 



The Pacas, hi addition to teeth very like those of the Agoutis, have a very 

 small toe on the internal edge of the fore foot, and one on each side, equally 

 small on their hinder one, making five toes everywhere. 



There is one species or variety fawn coloured, and another brown, both of 

 which are spotted with white, the Caviapaca, L. 



(1) Lagomys, i. e. Rat-Hares. (2) Hydrochcerus, water-pig. 

 (3) Chloromys, yellow rat. (4) Ccelogenys, hollow cheek. 



