No 
TRIBE MALLEACEA. 257 
C. Avicuraris. Lam. 1.—Bl. t. 63. f. 4.—An. du mus. vol. 
3. ¢. 2. f. 1,2.—Ostrea Semiaurita. JD. p. 281. ?—Gmei. 3335? 
—W.t.11.f. 77? Rounded-rhombic, compressed, submembra- 
naceous, blackish with many white rays, no sinus at the base. 14 
-- 13. S America. 
C. Mopiotaris. Lam. 2.—Del. t. 14. f. 2. Somewhat wedge- 
shaped, compressed, submembranaceous, reddish rufous, with a 
few white rays: beaks lower than the dorsal line, separated by a 
sinus. 24. New Holland. 
C. Niertna. Lam. 3.—C. Avicutaris. Sow. G. f. 1, 3.-—Reeve. 
t. 105. f. 1.—Ostrea Picra. W. t. 11, f. 82. Subovate, com- 
pressed, violet black, subradiated by very fine white lineoles : beaks 
minute and lower than the dorsal line. 2%. in length. Australia. 
C. Bicostatis. Lam. 4. Suboval, flat, blackish blue, upper valve 
with two longitudinal somewhat acute ribs : beaks terminal. Length 
33. New Holland. The original specimen in the French museum 
seems only an aged Nigrina. 
C. Virinis. Lam. 5.—E. vol. 2. p. 24. Ovate-oblong, some- 
what irregular, being unequally convex above, flattish concave be- 
low: greenish glaucous, dorsal edge with a somewhat tongue-shaped 
obliquely produced appendage; beaks terminal. 4. Australia. 
C. Myritorwes. Lam. 6. (and Puastanortera. Lam. 7.)— 
E. vol. 2. p. 24.—Ann. du Mus. vol. 3. p. 2. f. 8, 4.—Son. G. f. 
2.—Reeve. t. 105. f. 2.—Ostrea Picra. Gmel. 3399.—D. p, 
283. Oblong ovate, acute at the base, thin, violet with obscure 
rays; beaks internally, with crowded vaulted lamellw. 2. Red 
Sea. 
C. Fotiwm. Gray, Ann. Phil. 25.— Brande Journal, 15. t. 2. f. 
81.—Myritus F. W. 8S. ¢. 2. f 4. Ovate, whitish, rayed, com- 
pressed, anteriorly rounded, posteriorly winged. 
PERNA. 
Subequivalve, ILCUAL EES slightly distorted, of a lamellar texture ; hinge 
linear, marginal, composed of many furrow-like, parallel, and trans- 
verse teeth, “not inserted in the opposite furroms, between which che 
ligament is seated ; sinus for the byssus, vnemnot gaping, pos- 
terior, and placed under the extremity of the hinge, its sides callous. 
P. Eruiprium. Lam. 1.—E. t. 176. f. 2.—Ostrea E. Lin. 
1149.—D. p. 282.—Ch. f. 576.—List. t. 227. f. 62.—Klein t. 8, 
f. 18.— W. t. 11. f. 80. Greatly compressed, Pye brown, as 
broad as long, the hinge margin short, terminated anteriorly ina 
rounded off rectangle, from whence ane edge runs in a dilated shal- 
low sinus, to the Sonic bicular ventral margin ; ; posterior side the 
more produced, much incurved towards Ane beaks: internal nacre 
purplish, margins very acute. Var. (from Australia)... Whitish 
spotted with violet. 5. Indian Ocean. 
S 
