PATELLA. LIMPET 
135 
Shell thin, semitransparent, white or yellowish-white 
but not glossy, flat, thin, orbicular and entire at the margin, 
about which it is often a little rough with circular rows of 
minute tubercles, and rising from the centre into a conic- 
pointed crown, which appears to consist of a single protube¬ 
rance upon the top of which is a mammillary point, which in 
perfect specimens forms a single volution : inside smooth, 
glossy-white, furnished with a broad flat thin appendage, 
which is placed obliquely near one side, and a little twisted 
spirally: length about half an inch ; not so much in height. 
On the inside of oyster-shells, in the west of England, 
and Dublin bay. v. v. 
2. Patella orbiculata. Orbicular Limpet. 
Walker , pi. L f. 10. 
Shell orbicular, flat, opake, white, with the margin re¬ 
gularly toothed all round : crown central: inside with a 
transverse partition in the middle : minute. 
On the Sandwich coast ; very rare. 
13. With the crown entire , 3 to 10. 
r 3. Patella vulgata. Common Limpet. 
Lhtcr , pi. 535. f. 14— Pennant, pi. 92. f. 1 —Da Costa , 
pl, 1. f. 1,2, and 8— Donovan , pi. 14— Dorset Cat . pi. 23. 
f. 1 , 2 , and 8 . 
Shell with fourteen or more raised tubercled ribs and in- 
unnediate fine lines, forming as it were obsolete angles 
which cause the margin to be indented, generally conic, but 
eftenfiattish: color rufous brown, purplish, reddish or horn-^ 
color, often dull white with a plain margin when worn, and 
cfan oblong or roundish shape: crown nearly central and 
more or less elevated; inside glossy, white, flesh-color, 
blue, purplish, or horny, often iridescent and beautifully ra- 
-I'tev/ith yellow and chesnut; the bottom white or blueish- 
white, and generally opake : length reaching to two inches, 
and one and a half in height. 
This shell puts on so great a variety of appearances, that 
it is impossible minutely to pourtray them all; sometimes 
it is extremely conic, often much depressed; sometimes 
strongly tubercled longitudinally, with intermediate fine 
smooth lines; frequently appearing as if finely and regu- 
n 2 larly 
