256 MISCELLANEOUS. 



PLATE XXXV. 



FIG. 3. Clymene borealis in its tube. 



4. Anterior portion, enlarged. 



5. Entire specimen, enlarged ; anterior a ; posterior extremity, b. 



3. SIPHONOSTOMA. Plate XVIII. Figs. 10, 11, 12. 



As the subject of this paragraph bears some resemblance to what 

 might prove a species of the Siphonostoma of Otto,* taken by him in the 

 bay of Naples, I shall meantime abstain from disturbing nomenclature 

 by proposing the alteration of either. 



Before being aware of that naturalist's description, I had named it 

 provisionally Nereis gelatinosa. It occurred to me many years ago. 



As the preceding animal may present some elements of the Tere- 

 bella, so does this shew some analogies to the habits of the Nereis. 



In general appearance this creature is green, and quite gelatinous. 

 It extends three inches in length, by less than three lines in thickness, 

 and swims by contortions like the Nereis, continuing its activity at night 

 for a considerable time without interruption. Thus the smaller extre- 

 mity is always in advance, while what may be considered the anterior is 

 behind. 



The body is of a quadrangular figure, with about forty pencils, com- 

 posed of two long bristles, and a row of specks down the back. The 

 head or anterior extremity, consists of two thin leaves, capable of folding 

 together over the neighbouring parts, together with two yellow contrac- 

 tile tentacular organs. There are several setaceous organs, disposed in 

 two bunches, nearly twenty each, issuing from between the leaves, and 

 between the roots of those bunches is a single, round, black speck, re- 

 sembling an eye. 



The whole body is traversed by a reddish intestine. Other inter- 

 anea are also visible through the translucent integument, and the gra- 



* Vide Otto, apud Acta Phy^ico-Medica Academies Cresarcse Leopoldinss Carolina Na- 

 turae Curiosorum, torn. x. p. 628-633. Tab. LI. 



