138 PYRAMIDELLID.E. 



transparent, and of a lustrous polish : sculpture none, except 

 microscopical and extremely slight but numerous spiral striae, 

 which can only be detected at certain angles of light ; peri- 

 phery not keeled or angulated : colour very pale yellowish- 

 white or whitish, with a dark border below the suture, caused 

 by a thickening of that part : spire long and finely tapering to 

 a blunt point ; nucleus exposed, and twisted in different direc- 

 tions : whorls 5-6 (exclusive of the nucleus), rounded but 

 much compressed, and gradually enlarging ; the last occupies 

 rather more than one-half of the shell if viewed with the mouth 

 upwards, and about two-fifths if viewed with the'mouth down- 

 wards : suture slight, somewhat more oblique than in the last 

 species : mouth oval, inclining to oblong, narrow and acute- 

 angled above, rounded and scarcely expanded below ; its length 

 equals a third of the whole spire : outer lip rather flexuous, 

 not projecting beyond the periphery : inner lip thin, adhering 

 to the pillar on the upper part, and united with the outer lip ; 

 the lower portion is thickened, reflected, and curved : umbilicus 

 none, although full-grown specimens have a narrow chink : 

 tooth small, more prominent and conspicuous than in the last 

 species : operculum thicker on the inner than the outer side of 

 the mouth, coarsely striated, and sometimes having a white 

 streak down the middle. L. 0*1. B. 0-04. 



Habitat : Under loose stones and among seaweeds 

 at low-water mark, in the Channel Isles, South Devon, 

 Dorset, Cornwall, and Bristol Channel, as well as at Fish- 

 guard, Barmouth, and Cork; it is tolerably abundant in 

 the sublittoral zone at Exmouth. These are all the places 

 which I can vouch for ; O. turrita has been frequently 

 mistaken for the present species. This probably has 

 only a southern range, comprising the north of France 

 (J. G. J., Mace, Tasle, and Cailliand), Provence (Martin), 

 Antibes (Mace), Nice (Verany), Spezzia (J. G. J.), 

 Corsica (Susini), and Dalmatia (Brusina). Weinkauff 

 has enumerated it among his Algerian shells. 



The characters by which this species may be known 

 from the last are, narrower and slenderer, thin, trans- 

 parent, and much more glossy, having a longer and 



