COLUMBELLA. 357 



of the tentacles ; they appeared to be sessile and not placed 

 on any stalk or protuberance : foot lanceolate, long, narrow, 

 and thick, truncated, or bilobed and double-edged in front, 

 with angular corners, considerably expanding towards the tail, 

 which is in some specimens blunt and in others cloven. 



Shell between oval and oblong, rather solid, nearly opaque, 

 glossy : sculpture, narrow and rather sharp longitudinal ribs, 

 from 12 to 16 on the body- whorl, 11 to 20 on each of the two 

 preceding whorls, and nearly as many on the next whorl, where 

 they cease and are replaced by a remarkable kind of orna- 

 mentation which will be noticed presently ; the ribs are flexuous 

 on the body- whorl, and do not extend to the base, curved on 

 the upper whorls ; labial rib broad and thick ; the whole sur- 

 face is covered with numerous spiral stria?, which are minutely 

 and closely beaded, in consequence of their being decussated 

 by microscopic lines' of growth ; the striae at the base are 

 stronger than elsewhere ; the three or four top whorls that 

 form the apex have a dichotomous kind of sculpture, the lower 

 half of each being closely and minutely striated lengthwise, 

 and the upper half striated spirally with a Vandyke or scallop 

 pattern : colour whitish, more or less distinctly but irregularly 

 mottled with reddish-brown : epidermis, none perceptible : 

 spire somewhat turreted, varying in length, never slender ; 

 apex swollen, nipple-shaped and abrupt : whorls 8, compressed 

 but rounded, rapidly enlarging ; the last occupies two-thirds 

 of the shell : suture rather deep : mouth oval, comparatively 

 small ; length (including the canal) three-sevenths of the 

 shell : canal rather broad, abruptly bending to the left, and 

 ending in an obliquely curved notch: outer lip flexuous al- 

 though not much curved, somewhat expanding outwards ; the 

 sinus on the upper part is very slight, but distinct ; inside 

 thickened, and fluted by half a dozen tooth-like plaits, the 

 lowermost of which is the strongest : inner lip forming a glaze 

 on that side of the mouth, not much spread over the underside 

 of the shell ; its outer edge is thickened and well denned ; 

 some specimens have two or three obscure tubercles near the 

 base, as in typical species of Columbella : pillar curved, furnished 

 at the base with a strong and sharp flexuous fold : operculum 

 roundish-oval, thin ; lines of growth semicircular. L. 0-35. 

 B. 0-175. 



Habitat : Gravelly sand, in 85-95 f. about 25 miles 

 N.N.W. of Unst, with Limopsis aurita, Trochus amabilis, 



