434 PYRAMIDELLIDZA. 
termination ; there is at its clavate extremity a vertical, and 
a little below, a linear, transverse, deeply-impressed line, both 
having the appearance of a breach of continuity, though 
perhaps not really so. I mention these circumstances in 
this species to excite attention, as they are more developed 
than in such of its congeners as I have examined. The 
rostrum is conspicuously carried before the foot on the 
march, when it appears truncate, but at rest is rounded and 
sinuated as in C. pallida. The foot is also truncate, very 
slightly auricled ; the upper flap-skin, or real mentum, does 
not reach to its margin; it 1s narrow, not very long, atte- 
nuated and tapering to a rounded broad extremity, carrying at 
a short distance therefrom, on an obsolete lobe, a narrowish, 
pear-shaped, obliquely-striated, corneous operculum with a 
subelastic, rectangular apophysis, not notched in the centre, 
as the fold or denticle in this species is not usually visible ; 
but in those examples where it is more or less pronounced, 
the notch is proportionately marked. The tentacula are short, 
triangular and pointed, having large lateral membranes which 
coalesce to half their altitude, and are capable of assuming 
various shapes, as the auriform, the semitubular, &c., and of 
forming longitudinal folds on the stamens; being again, as if 
by magic, returned to a smooth, pointed, correctly bevelled, 
unfolded, symmetrical condition, coalescing regularly at the 
bases ; all these phases are effected by the will of the animal ; 
in short, the tentacula in this creature have an arcuated, leaf- 
like, broadly-subtriangular aspect, scarcely showing inflations 
at the obtuse tips; the eyes are at a little distance from the 
internal line of the bases. 
This elongated animal of sixteen volutions differs in no 
essential poimt, and scarcely m specialties, from its pigmy 
congeners of three turns, whether they be smooth, costated, 
toothed, or edentular ; emphatically showing a generic divi- 
sion of the family to be impossible, on reasonable grounds : 
all the species must, I think, range as Chemnitzie. The 
mantle is even, plain, scarcely having a trace of branchial 
canaliculation. 
The Ch. elegantissima is never marked with purple streaks 
