324 



tube short but broad, upturned, streaked across with purplish - 

 brown, or speckled like other parts of the body : tentacles tri- 

 angular and flattened, very short, widely diverging, spread out 

 at the base : eyes small, on broad lobes which surmount the 

 stalks, and placed near the outer base of the tentacles : foot 

 oblong, squarish, and double-edged in front, with short 

 angular corners, expanding at the sides, and bluntly pointed 

 behind ; sole often strawcolour or light orange : odontophore 

 having the central tooth oblong, broadly excavated above, 

 and armed below with three short equidistant and equal-sized 

 points ; lateral teeth palmated or deeply divided by twd wide 

 notches, which leave three thorn-like processes, the outermost 

 being longer and larger than either of the other two. 



SHELL conic above and expanded in the middle, with a short 

 and bluntly pointed base, solid, opaque, having scarcely any 

 gloss : sculpture, numerous spiral ridges, which are sometimes 

 regular, at other times alternately large and small, or arranged 

 in equidistant rows or series having one of the striae more pro- 

 minent than the rest ; the ridges do not extend to the suture ; 

 lines of growth microscopic and more conspicuous on the 

 upper whorls : colour yellowish- or reddish-white deepening 

 into fawn : epidermis very thin, nearly always wanting : spire 

 tapering to a blunt point ; apex mammiform : whorls 7-8, con- 

 vex and rather tumid, compressed on the upper part towards 

 the suture ; the last occupies more than two-thirds of the 

 shell : suture wide but not deep : mouth (exclusive of the canal) 

 angularly oval, considerably expanding outwards ; length alto- 

 gether about four- ninths of the shell : canal broad, turning to 

 the left, and ending in a deep obtuse-angled or curved notch : 

 outer Up semicircular, bevelled to a reflected and thickened 

 edge, not much contracted above ; inside smooth, often of a 

 deeper hue than the outside, and sometimes orange : inner lip 

 in aged specimens continuous with the outer lip, and making 

 together an angle corresponding with that of the mouth; it 

 varies in thickness, being frequently perceptible on the lower 

 side only : base strengthened by a thick and occasionally rugged 

 fold or ridge : pillar flexuoiis and broad, sharply angulated on 

 the lower part : operculum strong, marked by numerous semi- 

 elliptical striaa in the line of growth. L. 3'25. B. 2. 



Yar. 1. alba. White, and of a much larger size; body- 

 whorl and mouth often greatly expanded. 2. ventricosn. 

 Thinner; whorls more swollen. 3. striata. Spiral striae 

 stronger, and two on each of the upper whorls forming pro- 



