found on the South Coast of Devonshire. 75 
ocellated tentacula, 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 lacinia, 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 by My. Martin of Teignmouth : 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 
Sfrombus Pes Pclecani, 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 Bernard us; 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. 
Where this species of Sipunculus is found, old shells of Stromh. 
Pes Pelecani are not uncommon; and not a single instance oc- 
curred that such were 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. 
f Both these are figured in Martin's Marine Vermes, i. f.l./.S. 3. The former is 
also figured by Pallas in his SpicilegiaZoologica, x. t.l.f.8. and the latter may be Found 
in the British Zoology, iv. t.20.f. 10. 
L 2 we 
