HELIX. SNAIL-SHELL. 
45 
Shell flattish, a little convex on both sides, semitrans¬ 
parent, with a wide and deep perforation on the underside, 
strongly and irregularly wrinkled, and crossed in an oppo¬ 
site direction with very fine and minute strife, giving it a 
kind of shagreened roughness : spires six, the larger one 
sloping down on each side so as to form a sharp ridge on 
the margin, which rains spirally throughout the upper vo¬ 
lutions and marks their separation by a fine line, the edges 
of which appear slightly toothed or crenate by the wrin¬ 
kles: color dark horny, with deeper blotches: aperture 
transverse, nearly oval, narrowed to a kind of angle where 
it meets the keel, a little dilated in the middle, and round¬ 
ed beneath with a thin sharp white margin w T hich is slightly 
reflected, and . dilated and a little spreading towards the 
perforation: diameter three quarters of an inch \ height 
about three eighths. 
Woods, clefts of rocks, and old avails, v. v. 
2, Helix subcarinata. Subcarinated Snail-shell , 
Montagu, pi. 7- f* 0 — JFalker, , f. 22. 
Trochus rugosus. Brown, JVern. Soc. pi. 24. f. 5. 
Shell rather convex, semitransparent, white or pale 
nist-color, sometimes glossy, but generally appearing as if 
frosted: spires four, well defined and finely striate longi¬ 
tudinally, with two fine circular raised lines round the base 
of the body volution and one on the upper part, which last 
continues round the middle of the second volution, and is 
obliterated in the line of junction towards the top : from the 
lotver ridge at the base commences a semicircular channel 
which terminates in a large and deep perforation : aperture 
roundish oral; the outer-lip projecting and th n; inner-lip 
reflected, spreading into a sharp angle, and raised on the 
body of the volution: diameter one tenth of an inch ; height 
more than half as much. 
In fine sand, on the western coasts, Kent, and Dublin 
bay. t'. m. 
* 3. Helix planorbis. Bordered Snail-shell. 
Montagu , pi. 25. f. 1. 
Helix planata. Linn. Trans, viii. pi. 5. f. 14— Dorset Cat . 
pi. 20. f. 18. ' 
Shell 
