CEPHALOPODA. OCTOPODA. 5 
which occupies the lateral and posterior parts of the cavity. 
The anterior part of the brain, internally, receives the slender 
nerves from the region of the mouth, many of which often 
unite, before their junction with the brain: externally the same 
aspect receives the nerves of the legs, each of which is separate. 
The lateral aspects receive the optic nerve, which, in compari- 
son with the large ganglion, from which each passes, is very 
diminutive. The nerves from the intestines and posterior part 
of the sac join the brain at its hinder aspect. 
All the Cephalopoda inhabit the sea, and feed on crustacea, 
mollusea, and small fishes. They have the power of changing 
their colour, which had not escaped the observations of Ron- 
deletius and the older naturalists. Their eggs are deposited 
loose in the ocean, and are often thrown on shore during storms, 
and sometimes by the common movement of the waves. Those 
of the different genera vary in their forms ; for the most part 
they are agglutinated, and form bunches, which are commonly 
denominated Sea Raisins. 
Some of the species are esteemed delicious food, and are 
eaten in many parts on the shores of the Mediterranean. 
The best dissertation on the anatomical structure of this 
class of Mollusca, forms the first paper in Cuvier’s ‘ Mémoires 
pour servir 4 l’ Anatomie des Mollusques.’ 
ORDER I. OCTOPODA. 
Sac without fins. Lip not dilated beyond its reflected ring. 
Legs eight, united at their bases by a membrane, and having 
the inner aspect of each leg, from its base to its extremity, fur- 
nished with simple suckers. Cloaca without a valve. Back 
without a bone. 
We seem to possess but one species of this order in our seas, 
and this is referable to the genus Polypus. 
Genus |. Potyrvus. 
[loAvrovs, Aristotelis. 
Polypus, Plinii, Rondeletiz, Leach. 
Octopus, Lamarck, Cuvier, Duméril. 
