452 Mr. W. Clark on the Conovulidfc, 



out, and to his prospective intimation, that "future observations 

 may warrant possibly the modification of the characters of Par- 

 thenia for the reception of the Turbo unidentatus of ]\Iontagu and 

 its allies." The following notes will confirm the extreme saga- 

 city of this able malacologist. 



Chemnitzia eulimoides, Hanley. 

 Turbo et Odostomia pallida, auct., falsb Montagui. 



Animal of six spiral turns ; mantle plain ; foot short, truncate 

 in front, slightly auricled, but not eniarginate or hollowed out 

 in the centre as in its congener below, Chemnitzia acuta, rounded 

 posteriorly and terminating suddenly in a short point ; it is 

 powdered on its upper surface with pale gold-coloured minute 

 points, and in some specimens with sulphur-yellow dots ; beneath 

 the same colours prevail, though less intensely : it has a light cor- 

 neous, simple, not spiral, suboval operculum ; the head is a rather 

 short proboscidiform snout, marked on each side with a pale 

 yellow longitudinal line; the tentaeula are short, flattened, 

 triangular, not pointed, and bevelled like an awl, setaceous, and 

 in some animals suffused with sulphur-yellow; each has also 

 a longitudinal line running between the bevels ; the eyes are at 

 the internal jjoints of the basally coalescing tentaeula immersed 

 in the skin. The operculigerous lobe is inconspicuous, almost 

 obsolete, with scarcely a trace of lateral extensions. 



In this species the minute branchial plume was found in the 

 usual position attached to the neck and mantle, no head-lappets, 

 with scarcely the rudiments of a veil ; the anal pellets were ob- 

 served to be ejected from the right side ; the male organe gene- 

 rateur was not seen. This species scarcely differs from C. acuta : 

 the variation is in colour, and in the anterior part of the foot 

 being less hollowed out. 



There are five or six varieties slightly diff'ering in contour : their 

 principal habitat is at the back of the auricles of the Pecten oper- 

 cularis of the coralline zone, where they may be seen in clusters 

 of six to ten imbedded in animal mucus. This is a very common 

 species, and has long passed as the Turho pallidus of Montagu, 

 but his type, which still exists, proves the error. 



Chemnitzia acuta. 

 Odostomia acuta, auctorum. 

 Animal spiral ; ground colour white ; mantle simple ; foot 

 short, flake-white, in front deeply eniarginate, so much so as at 

 times of full extension to present the appearance of a second 

 pair of short tentaeula, rounding posteally to a point, with a 

 suboval corneous operculum on the posterior, scarcely to be ap- 



