from
The Collaborative International Dictionary of English v.0.48
Cephalopoda \Ceph`a*lop"o*da\ (s[e^]f`[.a]*l[o^]p"[-o]*d[.a]),
n. pl. [NL., gr. Gr. kefalh` head + -poda: cf. F.
c['e]phalopode.] (Zool.)
The highest class of Mollusca.
[1913 Webster]
Note: They have, around the front of the head, a group of
elongated muscular arms, which are usually furnished
with prehensile suckers or hooks. The head is highly
developed, with large, well organized eyes and ears,
and usually with a cartilaginous brain case. The higher
forms, as the cuttlefishes, squids, and octopi, swim
rapidly by ejecting a jet of water from the tubular
siphon beneath the head. They have a pair of powerful
horny jaws shaped like a parrot's beak, and a bag of
inklike fluid which they can eject from the siphon,
thus clouding the water in order to escape from their
enemies. They are divided into two orders, the
{Dibranchiata}, having two gills and eight or ten
sucker-bearing arms, and the {Tetrabranchiata}, with
four gills and numerous arms without suckers. The
latter are all extinct except the {Nautilus}. See
{Octopus}, {Squid}, {Nautilus}.
[1913 Webster] Cephalopodic