30 
MOLLUSCA. 
cavity ; in several species it contains a small, flat, and oblong shell, 
or at least a calcareous concretion in place of it. The respiratory 
Genus Vermetus . 
.... Scalaria • . . 
.... Deljihinula . 
Solarium. . . 
Rotella. . . . 
Trochus . . 
Monadonta 
Turbo . . . 
Planaxis . . 
Phasianella 
Turritella. . 
Ninth Family. 
Les Scalariens. 
Tenth Family. 
Les Turbinacds 
.Shell having no plaits on the 
columella, the edges of the 
aperture united circularly. 
Animal a vermicular Tra- 
chdlipode, and breathing wa- 
ter only. 
I~ Shell turretted or conoid, aper- 
I ture round or oblong, not 
I widened, having the edges 
disunited : they appear fur- 
I nished with an operculum. 
The animal breathes only 
L wmter. 
Genus Cerithium . 
Pleuromata 
Turbinella 
Cancellaria 
Fasciolaria 
Fusus .... 
Pyrula . . . . 
Struthiolaria 
Ranella . . . . 
Murex 
Triton 
Rostellaria 
Pterocera. . 
Strombus. . 
Second Section, — Les Zoophages, 
Animals feeding on animal substances only. 
‘Trachdlipodos with a project- 
ing or salient syphon, breath- 
ing water only, conveyed to 
the branchiae or gills by that 
syphon ; they feed upon ani- 
mal substances only, are 
First Division. — ") ^ marine, without jaws, and 
Species without £ provided with a retractile 
any permanent proboscis. Shell spirivalve, 
varix or thick- S inclosing the animal; the 
ened lip on the ^ aperture either canaliculated 
right margin. ® or notched at the base ; the 
right lip not changing its 
form by age, the canal more 
or less long ; all having oper- 
S cula. In the first division of 
this family, the additional 
grow'th is but slightly marked, 
in the second, it is distin- 
guished by thickened bands 
or varices, which remain on 
the external wdiorls, except 
in the genus Struthiolaria, 
which has only a thickened 
lip. 
Shell having a canal more or 
less long at the base of the 
aperture, the right side of 
which changes its form with 
age, and becomes w’ing- 
shajied ; a sinus at the lowxr 
part of the lip. These shells 
Second Family. y present the remarkable fact 
Les Aildes. \ of being totally different in 
form in an adult state, from 
that in the young ; a fact 
only observable in the G. Cy- 
prasa besides this family. 
The operculum of the ani- 
mals of this family is horny, 
long, and straight. 
Second Division. 
— All the species 
having perma- 
nent varices, or 
a thickened lip 
on the right side.^ 
