134 Description of New or Little known Species of 



Fam. Tremadotea. 



Have the under part furnished with cup-like discs, or 

 suckers, by which they adhere. 



Genus. Plan aria. 



Body flattened, depressed. Like the Flukes (which infest 

 the liver of sheep), they are bisexual. Very voracious, and 

 will even feed upon their own species. They multiply rapid- 

 ly in the ordinary way, and also by division of the body — 

 even spontaneous division as is alleged. Mutilated parts are 

 also very readily reproduced, and a partial division of the 

 body, will even produce an animal with two head or two tails, 

 according as the anterior or posterior end is cleft. Several 

 species inhabit the fresh waters, but larger ones are met with 

 on sea shores. — Cuvier. 



The species herein described are all marine, found on rocks 

 and sea weeds in the harbour and bays of Trincomalie. They 

 are exceedingly interesting creatures, some rivalling the tribe 

 of Dorididse in colours. They live for a long time in the 

 Vivarium. The mouth, situated in most of the species near 

 the anterior third of under part of medial line, opens and 

 dilates like that of a Sea- Anemone. Ova of most species 

 white, deposited in thin flakes on rocks and sea weed. 



Further investigation will, I believe, lead me to separate 

 the species into more than two genera ; the majority of species 

 correspond with JSL Duges DERASTOMA,in which there is one 

 opening, nearer the anterior edge than in Plan aria. The 

 presence of tentacles, or rudimentary ones, on the anterior edge, 

 or on the back, will also perhaps form a generic distinction. I 

 have attached the species without any appearance of ten- 

 tacular appendages, to a new gcnus,PENULA, mihi. The mouth 

 too in this genus is placed nearer the centre of under part. 



