MARINE MOLLUSCA OF THE UNITED STATES. 13 
Head short. Body elongate, cylindrical, acuminate posteriorly, 
truncated anteriorly, longitudinally adorned above with a violet 
zone. 'Tentacular arms with ¢wo series of small cups at the ex- 
tremities. The second and third pairs of sessile arms with a 
broad membranaceous fin on the inner edge of the ventral side. 
Shell thin, elongated. 
Atlantic Ocean, Mediterranean, Cape of Good Hope. 
Family LOLIGINID. 
The eyes are covered by the skin, without lids. Sessile arms 
with two rows of cups. Rings not convex externally, provided 
with a narrow, prominent edge on the middle of their width. 
Tentacular arms only partly contractile. 
Synopsis of Genera. 
Head separate from the body. Fin terminal, rhombic. 
Cups of sessile arms in two rows; lateral membranes with cups on the 
angles. Shell as long as the back. Louico. 
Head attached to back of mantle by a band. Fins short, dorsal, not ter- 
minal. Shell narrow, with a central and two marginal ribs. SEProua. 
Genus LOLIGO, Lamarck. 
Mém. Soc. Hist. Nat. 1799. 
These animals pursue their prey on the bosom of the ocean, 
swimming with great rapidity; fish and pelagic crustaceans, 
ianthinee and other oceanic mollusca, constitute their food; many 
individuals frequently unite and hunt in companies; their favorite 
time for scouring the surface being the evening after sunset. It 
is the favorite food of the cod, and with it one-half of all the cod 
taken at Newfoundland is caught. When the European species, 
I. magna, approaches the coast in vast shoals, five hundred sail 
of English and French ships engage in the fishery for bait. 
During violent gales hundreds of tons of them are often thrown 
up together in beds on the English coast. There are numerous 
species, inhabiting all seas. 
1. L. BREVIS, Blainville. Fig. 9. 
Journ. de Phys. 1825. 
Loligo brevipinna, Lesueur, Journ. Philad. Acad., iii. 282, t. 10, f. 1-8. 
1824. 
