( ija ) 



.XII. An Account of the Onchidiiim, a tieiv Genus cf the Clafs of Vermes^ 

 found in Bengal. By Francis Buchannan, M. D. A. L. S. 



Read June 5, 1798. 



^r'HIS animal, which I have always found on the leaves of the 

 •*- Typba elephaniina of Dr. Roxburgh, is very nearly allied to the 

 Slug or Limax ; but differs in fo many of the circumftances confi- 

 dered by Linnaeus as charadleriftic, that I imagine it will be found 

 to conftitute a new genus. To .this I would give the name Onchi- 

 dium, from the number of little tubercles with which the whole 

 upper part of the animal is covered. 



Vermes. MoUufca. Ore antico, corpore brachiato. 



ONCHIDIUM. 



Char. Gen. Brachia doo ad latera capitis. Tenfacu/a duo. Os 

 anticum. Anus pofticus, infra. 



Onchidiom Typha. 



Habitat in foliis Typhce elephantincv . 



The body in its ftate of reft is oblong, convex above, about an 

 inch long and three quarters of an inch broad, covering all the or- 

 gans. When the animal creeps it becomes linear, obtufe at both 

 ends, about an inch and a half or two inches long, and half or three 

 quarters of an inch broad ; and the arms and feelers of the animal 

 then become vifible. It is flat, black, and fmooth below ; above 



convex, 



