obtuse longitudinal striz ; greyish white, pale rufous 
or green, with a white tip.—1{. Cornwall and Devon, 
very rare. 
D. Lasratum. Turt. D. p. 38.—Nearly cylindrical, 
very slightly tapering and curved, semi-transparent, 
ivory white, covered, when fresh, with a black glossy 
skin, most finely and minutely striated longitudinally ; 
open at the larger extremity, the smaller end truncated, 
with the flattened surface somewhat undulated in a 
radiate manner, and finely striated circularly, from the 
centre of which projects an oval transparent process or 
lip, terminating in an oval aperture one side of which 
is cloven half-way down. 1%. Torbay. Breadth at the 
open end, one fifth. 
D. Lzve. Turt. D. p. 256. and Pouitum. p. 38. 
Somewhat cylindrical, slightly tapering and a little 
curved, semi-transparent, quite smooth and finely po- 
lished, white, with generally some irregular grey circular 
bands which grow darker and more combined together 
towards the narrower extremity; both ends open, the 
smaller very obtuse, not truncated, but rounded, with 
an oval perforation. 1. Torbay, very rare, not unlike 
the last. Breadth at smaller end,%, at the larger, 0,20. 
D. Semistriatum. Turt. D. p. 39. f. 68.—Very 
slender, tapering to a very fine point, glossy, transpa- 
rent, a little curved, open at both ends, quite smooth on 
A-2 
