555 



HYDRUS. WATER-SNAKE. 



Generic Character. 



Cbrpiis anterius gracile, sen- 

 sim crassescens, squamo- 

 sum. 



Cattda anceps* 



Body slender in front gradu- 

 ally thickening, scaled. 



Tail compressed. 



HE genus Hydrus is of late institution, and 

 comprehends those Serpents which naturally inha- 

 bit the water, whether fresh or salt, without ever 

 making their appearance on land, except when 

 driven there by accident. In their general ap- 

 pearance they are most allied to the Angues, and 

 are particularly distinguished by having laterally 

 compressed or flattened tails. This genus was 

 first instituted by Mr. Schneider, who has, how- 

 ever, admitted into it two species which seem more 

 properly to belong to the genus Acrochordus, and 

 which the reader will find so stationed in the pre- 

 sent work. 



Sea, or Water-Serpents, as Mr. Schneider ob- 

 serves, appear to have been known to the ancients ; 

 since they are mentioned by the Greek writers; 

 ^Elian quoting a passage from an anonymous au- 

 thor relative to snakes of very large size and \vith 



