icine aioe 
CLASS IX. MOLLUSCA. 
Remarks. [ include the whole grand division, 
Mollusca, in one class; though Cuvier subdivides 
it into the classes, Cephalopodia, head-footed— 
Pteropodia, wing-feoted—Guasteropodia, trunk- 
footed—Acephala, headless—Brachiopodia, arm- 
footed—Cirrhopedia, fibre-footed. As this classi- 
fication is founded upon the anatomical structure 
of the fleshy interior of the animals, it is manifest 
that they cannot be classified by their shells ac- 
cording to this system. As our investigations are 
mostly confined to the shells, I have adopted the 
Linnean sections for orders ; and prefixed an or- 
der for naked molluscous animals, which are not 
. of the radiated division. Could we always ob- 
tain the molluscous interior, the classification of 
Cuvier would be preferable. 
ORDER 1. NUDATA. 
Soft animals destitute of shells. 
Serra, (cuttle-fish,) body fieshy, receiving tlie. 
breast ina sheath, with a tubular aperture at its 
base ; arms 8, beset with numerous warts or suck- 
ers, and in most cases 2 peduncled tentacule ; 
head short; eyes large ; mouth resembling a par- 
rot’s beak. In sea. This is the animal called 
the polypus by the ancients ; but that name is very 
differently applied by modern naturalists. 
C110, body oblong, nayant, generally sheathed, 
and furnished with 2 dilated membranaceous 
arms or wing-like processes ; tentaculz 3, besides 
2 in the mouth. ° In sea. 
