principally marine, found. on the South Coast of Devonshire. 93 
exterior one first falls off, otherwise the part separated appears 
to continue in that moniliform state. This, however, may be a 
forced action from confinement in a glass of sea water, and one 
division at the extremity is the order nature most likely pursues. 
It must however be admitted that our knowledge with respect to: 
these inhabitants of the deep is extremely limited, since they can. 
only be examined when taken from their natural abode: the form 
of these creatures is nearly all we may expect to become ac- 
quainted with, for their ceconomy is concealed from us by that 
insurmountable barrier which no philosopher can pass. 
The faculty this animal possesses of separating into so many 
parts renders it quite impossible to preserve a perfect spe- 
cimen. 
It must be confessed that Muller is referred: to with doubt, as I 
could not discover any regular series of papillz in the present 
_ subject, which that author describes in his; nor was there any 
appearance of pinnz on the sides of the tentacula, as repre- 
sented by Muller; and yet, if the figure of this is compared with. 
. those of that author given of the natural size, a difference is 
scarcely obvious. With similar doubt Gmelin is. quoted, who 
refers to Forskahl as well as to Muller; and if we may judge from 
the figure given of Holothuria inhaerens in the Naturalists Mis- 
cellany, vol. viii. tab. 260, (the author of which quotes Gmelin, 
and like him refers to the Fistularia reciprocans of Forskahl,) the 
H. digitata is perfectly distinct. Probably the former author did 
not consider the species given by Muller to be the same as re- 
ferred to in Forskahl, as he has not quoted Zoologia Danica :. 
indeed there can be no doubt but the H. inherens of Nat. Misc.. 
and Zool. Dan. are perfectly distinct. ! 
THALASSINA. 
