found on the South Coast of Devonshire. 75 



occllatcd tcntacula, receding by degrees at the mouth until the 

 more slender part of the body is, as it were, turned outside in* : 

 the mouth is surrounded with lacinicc, or short feelers : the colour 

 is livid, and the whole animal smooth and firm, except about the 

 middle, or just behind the part which increases in size, and where 

 the vent is placed, which is verrucose. 



Its utmost length appears to be between three and four inches ; 

 the diameter of the largest part, one-eighth of an inch. 



Of this genus of Intestina there do not seem to be more than 

 two species hitherto described : the >S'. saccatus was supposed only 

 to inhabit the American and Indian seas, till it was discovered 

 to be British bv Mr. Martin of Teismmouth : S. nudus has been 

 longer known to be indigenous to our coasts, and is not uncom- 

 monly found buried in sand near low water mark-j-. 



This animal is parasitical, taking possession of the old shells of 

 Strombus Pes Pckcani, to which it seems peculiar, for in no one 

 instance have we been able to discover it elsewhere. It is remark- 

 able that the aperture of this shell, which is contracted or nar- 

 row, is ill calculated for the habitation of Cancer Bernardus ; and 

 of course becomes better adapted for the dwelling of the Sipun- 

 culus, as not likely to be destroyed or molested by that predatory 

 insect. 



A\ here this species of Sipunculus is found, old shells of Stromb. 

 Pes Pe/ccani are not uncommon; and not a single instance oc- 

 curred that such Avere not taken possession of by this animal : 

 and as the Hermit Crab is more plentiful in the same place than 



* This circumstance, which has not been generally noticed, seems to be a strong 

 generic character. 



t Both these are figured in Martin's Marine Vermes, i. t.l.f.2. 3. The former is 

 also figured by Pallas in his Spicileg ia Zoclugica, x. M ./. 8. and the latter may be found 

 in the BritLh Zoohigy, iv. 1,-20. f. 10. 



l 2 we 



