XXVI 



1 DORIS. 



Body creeping, oblong, and flat beneath ; mouth 

 placed below on the fore part : vent behind, ufually on 

 the back, and furrounded by a fringe: feelers two or 

 four, feated on the upper part of the body in front, and 

 retraftile within their proper receptacles. 



The Doris is the inhabitant of the Chiton : many ele« 

 gant fpecies are mollufca. 



2 TRITON. 



Body oblong ; mouth with an involute fpiral probof- 

 cis ; tentacula or arms twelve, fix on each fide, divided 

 nearly to the bafe, the hind ones cheliferous. 



The Triton is found to inhabit Balanus and Lepas : 

 and one fingle fpecies inhabits the fea in a mollufca ftate- 



3 ASCIDIA. 



Body fixed, roundifh, and apparently iffuing from a 

 flieath : apertures two, generally placed near the upper 

 part, one beneath the other: adhere by their bafe to 

 rocks, fliells, and other marine fubftances ; are more or 

 lefs gelatinous, and feem to have no other powers of mo- 

 tion 



