402 PHYLUM MOLLUSCA. 
Third Type of Mortusca. The Common Cuttlefish 
(Sepia officinalis), one of the Dibranchiate Cephalopods 
Habits.—This common cuttlefish is widely distributed, 
especially in warmer seas like the Mediterranean. Unlike 
Octopus, which usually lurks passively, Seféa is an active 
swimmer; it moves head foremost by working the fins 
which fringe the body, or it jerks itself energetically back- 
wards by the outgush of water through the funnel. It likes 
the light, and is sometimes attracted by lanterns. The 
beautiful colours change according to external conditions 
and internal emotions; and a plentiful discharge of ink 
Fic. 216.—Side view of Sesza.—After Jatta. 
often covers, its retreat from an enemy. Its food includes 
fish, other molluscs, and crabs. In spring the female 
attaches her encapsuled eggs to seaweeds and other 
objects, and often comes fatally near the shore in so doing. 
The cuttles are caught for food and bait. The “cuttle 
bone” and the pigment of the ink-bag are sometimes 
utilised by man. 
External appearance.—A large Seféa measures about 
to in. in length and 4 to 5§ in breadth; the body, fringed 
by a fin, is shaped like a shield, the broad end of which 
bears a narrowed head, with eight short and two long 
sucker-bearing arms. Besides the diffuse pigment cells, 
there are bands across the “back.” The large eyes, the 
parrot-beak-like jaws protruding from the mouth, the spout- 
like funnel on the neck, and the mantle cavity, are con- 
spicuous. Beside the eyes are the small olfactory pits; 
