LECTURE X.' 
127 
elegantly formed worm of about half an inch in 
length, not uncommon in stagnant waters, and call- 
ed the Nais proboscidea, or long-snouted Nais, since, 
if accurately inspected, it will appear to be furnish- 
ed with a very long, transparent proboscis, which 
continues always stretched out, the animal being 
incapable of retracting it. This species, like some 
other of the smaller Vermes, possesses in a high 
degree the power of reproduction, and if cut or 
broken, each part will survive, and reproduce its 
defective organs. 
But, by far the most remarkable of all the Lin- 
naean genera of the Mollusca nuda or Shell-less Mol- 
lusca is that of Sepia^ in English Cuttle or Ink- 
Fish. The genus Sepia or Cuttle is distinguished 
by having a fleshy and somewhat lengthened body, 
seated or enveloped in a kind of sheath, reaching 
nearly to the head of the animal. The head is 
furnished with very large eyes, and a horny, cen- 
tral beak, consisting of two mandibles, and resem- 
bling that of a parrot. Round the base of the 
head arise eight long arms, in a radiated direc- 
tion, and in some species are two additional 
arms, of a much greater length than the rest. All 
these arms are beset, on their internal surface. 
