146 PYRAMIDELLID^. 



towards the point, where it assumes a clavate or hammer-like 

 appearance, becoming thick, angular, bevelled to a sudden edge, 

 and straight or truncated in front : tentacles very short, not 

 much folded, terminating in indistinct flake-white lobes ; the 

 lateral membranes, which are not so extensive as in other 

 species, coalesce and form a shallow veil : eyes very close to- 

 gether, exactly at the internal bases of the tentacles, '' not 

 immersed, but a little elevated on minute prominences : " foot 

 rather broad and truncated in front, without the usual ear- 

 shaped points at the corners, becoming a little constricted be- 

 hind, and having a very rounded extremity: opercular lobe 

 simple. (Clark.) 



Shell conic-oblong with a rather narrow base, thinnish, 

 semitransparent and somewhat glossy : sculpture, rather strong 

 longitudinal ribs, which are flexuous on the body-whorl and 

 extend to the base, and are curved on the next two whorls, the 

 upper ones being smooth ; there are about 25 ribs on the last 

 whorl, 20 on the penultimate, and 15 on part of the ante- 

 penultimate whorl, where the ribs cease altogether ; the inter- 

 stices of these ribs are crossed by finer and thread-like spiral 

 or transverse striae, of which about a dozen may be counted on 

 the body-whorl, 7 or 8 on the next, and 5 or 6 on the suc- 

 ceeding whorl ; the striae do not extend to the suture ; the mu- 

 tual intersection of the ribs and striae gives a finely cancellated 

 or reticulated appearance : colour whitish : sjnre produced, 

 sUghtly turreted ; nucleus raised in front or on one side, and 

 twisted inwards : whorls 4 (besides those forming the nucleus), 

 convex, and rather quickly enlarging ; the last occupies nearly 

 three-fifths of the shell : suture deep and channelled, some- 

 what oblique: mouth oval, scarcely contracted above or ex- 

 panded below ; its length is almost two-fifths of the whole 

 spire : outer lip not much curved, abruptly inflected on the 

 periphery : inner lip thin on the upper part, continuous with 

 the outer lip in adult specimens, thickened, reflected, and in- 

 clining to straight on the lower part, w^hich is twice as long 

 as the other : umbilicus sHght, forming a narrow chink behind 

 the inner or pillar-lip : tooth very retired and inconspicuous, 

 consisting of a narrow oblique fold, which on breaking the 

 shell may be seen winding round the pillar : operculum rather 

 thin and delicately striated. L. 0-125. B. 0-05. 



Habitat : Coralline zone on the coasts of Devon and 

 Cornwall (Montagu, Barlee^ and others) ; Guernsey, 



