164 
three, smooth, longitudinally ob!ong ; aperture obleng, 
body lip a little thickened and flattish. 0,08. Inter- 
stices of rocks covered at high water, Devonshire. 
TrireE.— MACROSTOM®. 
Auriform, with the aperture very wide and the mar- 
gins disunited ; without an operculum or columella: 
Grenvus.—SIGARETUS. 
Subauriform, suborbicular ; inner lip short and spirally 
intorted ; aperture entire, dilated, rounded oblong, 
not nacreous ; margins disunited. 
S. Perspicua—Heix P. Lin. not Gmel.— 
S. Hatioromwets. F. p. 360.—Buxiia H. Mont. p. 
211. 4. 7. f. 6.(Animal—vignette. 2. f. 6.)—Inn.T.8. 
p. 123.—Dor. Cat. p. 43. ¢. 22. f.5.*—Heurx H. 
var.? D. p. 973.—S. Convexus. Blainv. t. 42. 
jf. 2.—Suboval, ear-shaped, extremely thin, white, 
pellucid, glossy, smooth but not quite destitute of 
wrinkles; aperture oval, not quite extending to the 
apex which is small, obtuse, and laterally convoluted, 
scarcely making two volutions ; the body of the shell 
very small and only turning a little inwards spirally ; 
inner lip visible to the end. %...2: Devon, rare. 
S. Tentacutatus. Ff, p. 360,—LaMEL.aria, T. 
