158 
as well as by other less striking characters. The animal has a 
large fleshy cylinder, containing two tubes, one for respiration and 
the other evacuation, situated at the posterior extremity. The 
foot is small and compressed, placed at the opposite extremity or 
near it. 
It is a littoral genus, inhabiting estuaries and near the mouths 
of rivers. 
Blainville unites this genus with Ligula, Leach, under the 
2 ;eneric name Lutricola. Lamarck describes eleven recent and 
one fossil species. 
Lutraria lineata. — Specific character.. Posterior margin 
with a reflected edge and submarginal carinated line. 
Lutraria lineata., nohis. Jour. Acad. Nat. Sc. vol. 2,^. 310. 
Lutraria papyracea? Lam. Anim.sans Vertehr. vol. 5, 470. 
Ohs. The elevated line of the posterior submargin and the re- 
flected posterior edge are very characteristic, distinguishing this 
species from all others, excepting the figure 2 of the plate on 
Lutraria in the second volume of Mr. Sowerby’s excellent work 
on the G-enera of Recent and Fossil Shells.’^ Our shell is much 
shorter on the posterior end than his figure, which he refers with 
doubt to the papyracea of Lamarck ; a difference which, however, 
may be attributable to an inequality of age, as it becomes more 
elongated anteriorly in the older shell. Whether or not the present 
species is the same as that of Lamarck we cannot at present de- 
termine, but it is without doubt closely allied to it. Still, how- 
ever, it does not agree with the figure in the Encycl. Meth. 257, 
fig. 2, a, b, quoted by Lamarck. Pi. 9. 
Palumna. — Shell fluviatile, conical, subovate or suboval, cov- 
ered by an epidermis ; spire moderate ; whorls convex ; aperture 
longer than broad, angulated above, simply rounded at base ; la- 
brum simple, acute, united above to the extremity of the labium ; 
labium simply arquated ; operculum corneus or coriaceous, subor- 
bicular, slightly angulated above. 
Ohs. The species of this genus were widely separated from each 
other by former authors, and referred to the Genera Helix, Turbo, 
Bulimus, Nerita, and Oyclostoma ; but Lamarck selected and em- 
bodied them under the present designation, and they now consti- 
tute a natural group. 
