NAKED MOLLUSKS. 303 
SECTION II. 
FOSSIL REMAINS OF NAKED MOLLUSKS, PENS, AND 
INK-BAGS OF LOLIGO. 
It is well known that the common Cuttle Fish, 
and other living species of Cephalopods,* which 
have no external shell, are protected from their 
enemies by a peculiar internal provision, con- 
sisting of a bladder-shaped sac, containing a 
black and viscid ink, the ejection of which 
defends them, by rendering opaque the water in 
which they thus become concealed. The most 
familiar examples of this contrivance are found 
in the Sepia vulgaris, and Loligo of our own seas. 
(See PL 28, Fig. 1.) 
It was hardly to be expected that we should 
find, amid the petrified remains of animals of the 
* The figure of the common Calmar, or Squid (Loligo Vul- 
garis Lam. — Sepia loligo of Linnseus), see PI. 28, Fig. 1, 
illustrates the origin of the term Cephalopod, a term applied to 
a large family of molluscous animals, from the fact of their feet 
being placed around their heads. The feet are lined internally 
with ranges of horny cups, or suckers, by which the animal 
seizes on its prey, and adheres to extraneous bodies. The 
mouth, in form and substance resembles a Parrot's beak, and is 
surrounded by the feet. By means of these feet and suckers the 
Sepia octopus, or common Poulpe (the Polypus of the ancients), 
crawls with its head downwards, along the bottom of the sea. 
