352 NASSID.E. 



finer and more thread-like than usual ; the intercrossing of 

 the sculpture produces a tubercular or nodulous decussation, 

 the tubercles being transversely elongated ; top whorls quite 

 smooth and glossy ; the basal part is separated from the rest 

 of the body- whorl by a deep and oblique groove (as if pinched 

 up), and has about a dozen oblique ridges or striae, which 

 become slight and indistinct towards the base ; the whole sur- 

 face (especially the interstices of the ridges) is covered with 

 microscopic and close-set longitudinal lines : colour pale buff 

 or yellowish-white, passing into purple, pink, orange, or brown, 

 and often variegated by three broad and interrupted bands of 

 reddish-brown, or by a narrow and broken white zone ; it is 

 occasionally milk-white; the base has a purplish-brown or 

 chocolate blotch, the mouth is white (rarely pinkish), and the 

 tip frequently purple or pink : epidermis thin and somewhat 

 fibrous, usually abraded but sometimes retained in the inter- 

 stices of the ridges : spire rather short, and abruptly termi- 

 nating in a nipple-shaped point : whorls 8-9, convex, indis- 

 tinctly angulated in the middle, and rapidly enlarging ; the 

 last occupies about three-fifths of the shell: suture rather 

 deep : mouth oval, comparatively small, acute -angled above ; 

 length (including the canal) nearly one-half of the shell: 

 canal narrowish, obliquely recurved to the left, ending in a re- 

 markably deep notch, which is very conspicuous when the shell 

 is placed with its mouth downwards : outer lip somewhat com- 

 pressed and nearly straight above, semicircular in the middle ; 

 edge rather thin, and slightly reflected outwards ; inside thick- 

 ened, as well as strengthened by the labial rib, and fluted by 

 8-10 narrow plaits : inner lip forming a thick coat of enamel, 

 which is spread over a considerable portion of the under side 

 of the shell, and folded behind the pillar ; it has just below the 

 outer lip a plait or ridge-like process that partially winds 

 round the upper part of the pillar, and a few other irregular 

 and obliquely transverse processes of the same kind (or 

 wrinkles) towards the base : pillar curved, furnished at the 

 base with a flexuous fold : operculum ear-shaped, light horn- 

 colour, more or less serrated on the outer edge, and often 

 deeply jagged or notched on the inner edge near the base ; 

 lines of growth numerous, and obliquely elliptical. L. 0-6. 

 B. 0-3. 



Var. 1. major. Much larger. 2. minor. Dwarf. 3. simu- 

 lans. One of the ribs on the body- whorl varicose. 



