94 Couthouy's New Species of Mollusca 
sides of the neck; foot short, thick, and muscular, 
oblong, and when wholly expanded, appearing nearly 
quadrangular; head elongated, rounded superiorly, not 
separated from the neck by any distinct line; from its 
superior, posterior sides arise two tentacule about one 
eighth of an inch in length, terminating in a fine point, 
but destitute of the bristly process, “filet sétacé,” 
mentioned by Lamarck in his generic description of 
Scalaria. The eyes are small, black and shining, situate 
laterally and posteriorly at the base of the tentacule, 
and not as in the animal described by Lamarck and 
Blainville, near their middle; mouth rather large, 
rounded, and externally furnished with numerous strong 
folds or wrinkles; no proboscis was at any time pro- 
truded; the operculum is horny, strong, opaque, shining 
and pauci-spiral. 
SurgLL turreted, tapering to an acute point, imper- 
forate, opaque, color varying from dull bluish to brown- 
ish white; whorls nine, contiguous, slightly convex, 
traversed longitudinally by strong, equidistant, com- 
pressed, nearly regular ribs, of a whiter color than the 
rest of the shell, to the number of ten on the body- 
whorl, which is circled at its base, by an angular line 
commencing at the superior portion of the columella, 
and running parallel to the sutures. The ribs do not 
terminate at the sutures, but extend each one upon that 
next above it, in such à way as to render the summit of 
each somewhat angular; the interstices of the costa are 
strongly impressed with seven or eight revolving stri; 
aperture regularly oval, lip bordered externally by a 
strong rib, slightly emarginate at the base, rounded and 
slightly reflected in its columellar pesi and IRRA 
of a pure white. 
