[ H4 ] 
THE 
O F 
PART III. 
Of S H E L L-F I S H. 
HELL-FISH are animals with a foft body, covered by, or included in, a 
firm, hard, and, as it were, Jlony covering, compofed of one or more parts, and 
more or lefs moveable at the animal's pleafure. 
The genera of the Shell-ffh are extreamly numerous, and the fpecies, under 
many of them, are alfo very much fo, The animals, included in thefe hard, external cafes, 
have moft of them the characters of one or other of the genera of the Gymnarthria before 
defcribed, and might be reduced under the fame genera with the naked ones ; or the whole 
feries of Shell-ffh might be arranged according to their characters ; but as thefe charac¬ 
ters are few, and the bodies themfelves very numerous ; and as the external coverings or 
Jhells are extreamly different in their form and firuClure, and thefe differences are fiuff- 
ciently obvious, determinate, and numerous ; it will tend more to the making natural 
hiftory an eafy and an univerfal fiudy, to arrange this part of it according to the dif¬ 
ferences of the Jhells themfelves, than thofe of the included animals. There is this far¬ 
ther confederation alfo in favour of this arrangement , that the bodies of the animals them¬ 
felves are very rarely feen, and never preferved in-collections, whereas the Jhells make an 
eminent figure in them ; and that many of them have been only met with, empty of the 
included animal. 
I Jhall not fo far difregard, indeed, the form and firuClure of the included animal, 
as to leave the reader in the dark as to what it is j but, as all of the fame 
genus are the fame in this refpeCl, it will be fiffcient barely to mention which of the for¬ 
mer genera of Gymnarthria they belong to, after the generical characters oj the fhell . 
Thus IJhall not omit to fay, that the animal inhabiting the patella is a Umax ; that the 
animals inhabiting the fever alJhells of the cochlea, the nerite, the buccinum, the turbo, 
the trochus, the voluta, the murex, the purpura, and the lyra, are all limaces alfo •, and 
that the inhabitants of the concha Veneris and auris marina are all of the fame genus: 
that the inhabitant of the dentalium is a Nereis, that of the nautilus a Sepia, that of 
the oftrea, the peClen, and the like, a Tethys, and that of the concha anatifera and 
balanus a Triton. 
The mention of' this, at the head of the genus, will convey a fiffcient idea of what the 
animal is that inhabits the outer cafe, which is the objcCl of our more immediate atten¬ 
tion ; and 1 fatter my felfi that it will appear much better to pay this fecondary regard 
to theform of the body of the creature, than, for the fake oj arranging thofe of the fame 
firuClure in the lefs obvious part together, to have brought into one genus the auris ma¬ 
rina, the concha Venerea, the buccinum, the voluta, and the patella . 
* The 
