280 MOLLUSCA.—CLASS V. CEPHALOPODA. 
any other of the class; it is larger and of more intricate structure, and 
the shell is partially modified into a kind of gelatinous, crystalline inte- 
gument. The species represented in our plate was the only one known 
to Lamarck ; there have, however, been three or four discovered since his 
time by MM. Quoy and Gaimard, and described and figured by those assi- 
duous malacologists in the ‘‘ Zoology”’ of their ‘ Voyage de l’Astrolabe.’ 
The shell of Cymbulia, or more properly its integument, may be de- 
scribed as being cartilaginous, crystalline, and of an oblong, slipper-like 
shape, truncated posteriorly and open anteriorly, the aperture being 
nearly lateral. 
Example. 
Pl. CCXCVI. Fig. 1 to 3. 
CymBuuia Peroni, Cuvier, Régne Animal, vol. ii. p. 380. Péron, An- 
nales du Muséum, pl. 3. f. 10 to 12. 
Cuass V. CEPHALOPODA. 
Animal corporis parte abdominali pallio amplo, sacciformi, circumtecta, 
testa munitum ; anticé capitatum, capite distincto, oculis duobus 
prominulis instructo, brachiis, quasi tentaculis, flexilibus agillimis, 
plus minusve elongatis coronato ; ore terminali, maxillis duabus 
corneis armato. Branchiz aut due aut quatuor, subfoliiformes, 
intra pallium celatze. 
Testa loculosa vel illoculosa. 
The Cephalopoda, or Head-walking mollusks, so called from their man- 
ner of crawling on their tentacles with the head downwards, are the most 
highly organized of the grand invertebrate moiety of the Animal King- 
dom, and come next in order, therefore, to the Fishes, the most simply 
organized of the vertebrate portion. They present a system of organiza- 
