Tritbnm pinnatifida. 



61 



with a globular head, which is certainly imperforate. The 

 stomach is a loose thin-plated extensible bag ; to the inner 

 surface of which are attached numerous filiform caeca, that, 

 after removal from the body, retain their irritability for a 

 long time, and writhe themselves like a knot of worms. 

 ifig. 3. c.) 



Both our specimens were found near low water-mark, ad- 

 hering to the fronds of jFucus siliquosus. 



I may remark that in the figure which Montagu has given 

 of Lucernaria auricula {Lin. Trans, ix. 113. tab. 7. fig. 5.), 

 there is no appearance of marginal tubercles between the tufts 

 of tentacula, whence it may be inferred that it has been 

 drawn from a specimen of the present species with only seven 

 arms. 



28. Trito v nl4 pinnati'fida. {fig. 4.) 

 CI. Mollusca, Ord. Nudibranchia, Fam. Tritoniaokz?. 



Synonymes. — Tritdnia pinnatifida Cuv., Reg Anim., iii. 53. note; Fleming, 

 in Edin. Encycl., xiv. 619.; Flem. Brit. Anim., 284. Dork pinnatifida 

 Montagu, in Lin. Trans., vii. 78. pi. 7. fig. 2, 3; Turt., Brit. Faun., 134; 

 Penn. y Br. Zool., iv. 83., edit. 1812. 



In the works here quoted, except in The Linncean Trans- 

 actions^ the reader will find nothing to reward the labour of 



referring to them, 

 for the descriptions 

 they contain of this 

 singular mollusc 

 are borrowed from 

 Montagu, who dis- 

 covered the species, 

 and who alone 

 seems as yet to 

 have written any 

 thing about it. On 

 the shores of De- 

 von T. pinnatifida 

 is not uncommon, and I have often found it on corallines, shells, 

 and rubbish, brought up on the hand-lines of the fishermen 

 in Berwick Bay ; but when out of water and contracted, the 

 keenest eye may not detect such a small and shapeless crea- 

 ture, for before it will display itself, as delineated in our 

 figures, it must be provided with fresh sea water and left 

 undisturbed. It creeps slowly, and it is capable of swimming 

 on the surface in a reversed position. 



The body is half an inch in length, linear-oblong, yellowish- 

 brown, truncate anteriorly, tapered to the posterior end, the 

 back plane, with the branchiae in a single row along the 



Tritbnia pinnatifida. 



