61 
the interstices; anterior end mostly gaping,rarely scime- 
what closed; inside white with frequently a chocolate 
blotch at one end, margin entire, hinge subterminal. 
2...4. Torbay, in Rocks. 
V. Perrorans. Lam. 1.—Turt. B. p. 29. t. 2. f,. 
15 to 18.—F. p. 451.—VeEnvus P. Mont. p. 127. t.3. 
Jf. 6.—ILin. T. 8. p. 89.—Pen. 4. p. 111.—D. p. 206. 
—Turt. C. D. p. 245.—Variable in shape, more or less 
oblong, angularly truncated at one end (sometimes 
rounded at both ends or kidney-shaped and indented) 
very inequilateral, with transverse striz which become 
lamellar anteriorly,and minute radiating ones; brownish 
or yellowish white, with sumetimes a few purple 
broken rays and linear ziczacs; inside white, glossy, 
with mostly a purple blotch at the larger end, margin 
entire; hinge with three erect, long, and somewhat re- 
curved teeth in each valve, two of them cloven, the 
lower one in the right valve and the upper one in the 
left, entire and much the smaller. 1...22. In rocks, 
common. The young are compressed, white variously 
marked with purple blotches anteriorly. 
Trrpe.—NYM PHACEA. 
Never having more than two cardinal teeth in the same 
valve, often gaping at the lateral extremities ; liga- 
ment external, umbones usually projecting outwards, 
