431 PYRAMIDELLIDJB. 



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 is 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 sernitubular, &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 point, and scarcely in 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 Chemnitsiae. The 

 mantle is even, plain, scarcely having a trace of branchial 

 canaliculation. 



The Ch. eleyantissima is never marked with purple streaks 



