FAMILY DIDELPHIDJE ; CHEIRONECTES. 345 



to have been mistaken for them : others are about the size, and 

 have the appearance and habits, of the Rat. The only other genus 



included in the family of Didelphidae, is the Cheironectes, or 

 Yapoch, an inhabitant of the smaller streams and rivers of Brazil 

 and Guiana. This interesting animal bears a strong general resem- 

 blance to the Otter, but is much smaller. It is incapable of climbing, 

 but lives in holes along the banks of the rivers it frequents ; and 

 it is provided with cheek-pouches, in which it stows away the 

 food it obtains in the stream, consisting of fresh-water Crustacea, 

 the larvae of insects, the spawn of fishes, &c. In tMs genus we 

 do not find an opposable thumb on either foot ; and the toes of 

 the hind-feet are webbed. It differs from the Opossums aiso, in 



