164 TESTACEOUS MOLLUSCA. 
P. Srrratutaris. Lam. 13.—Reeve. Ic. f. 27%  Ovate 
heart-shaped, transverse, reddish. white under a brown silky epi- 
dermis, with very numerous fine longitudinal strie ; beaks rather 
oblique ; within white with a large stain of reddish brown. 14-— 
New Holland. 
P. Inrermepius. Brod. Z. P. 1832.—Reeve. Ic. f. 1. 
Suborbicular, subglabrous, subdepressed, whitish, with pale 
chesnut radiating zones near the umbo, with rather distant radiating 
decussated strize : inside white, the margins crenated: epidermis 
somewhat velvety. 15%,..13.—Jquiqut. 
P. Ovarus. Brod. Z. P. 1832.—Reeve. Ic. f. 2. Exactly 
oval, longer than broad, convex, glabrous with very minute trans- 
verse lines, whitish, the umbones pale chesnut: inside white, the 
margin crenulated; the epidermis somewhat downy. 13..1}.— 
Pacific. Closely resembling the last, but much more elongated. 
P. Lineatus. Reeve. Z. P. 1843.—Reeve. Ic. f. 25. Orbi- 
cular convex, slightly auriculated, decussately striated, longitudinal 
striee the stronger, whitish clouded anteriorly and about the middle 
with chesnut spots and vividly painted posteriorly with dark lon- 
gitudinal lines: umbones central. 13.—West Indies. Closely 
allied to Pennaceus. 
P. Macuuatus. Brod. Z. P. 1832.—Reeve. Ic. f. 4. Orbi- 
cular, slightly eared, subequilateral, convex, whitish spotted with 
chesnut, somewhat decussated with thick set radiating striee: in- 
terior white, margin crenated: epidermis brown and downy. 
23, .28.—Central America. 
P. Giganteus. Seeve. Ic. f. 3.  Orbicular, very convex, 
(depressed when young) solid, large, with longitudinal close and 
regular striz and almost obsolete grooves; white stained with 
chesnut towards the ventral edge, middle and umbonal portion 
profusely and vividly painted with waved reddish brown spots 
touching each other for the most part on both sides: interior 
white, margins of the adult of bright shining chesnut, crenated : 
epidermis thick and hairy. 4.—California. Allied to the Un- 
datus of Linneus. 
P. Muuristriatus. Desh.— Reeve. Ic. f. 42.—Arca M. 
D. p. 224.—A. Srriata. Gmel. 3308.—W. t. 9. f. 41.—Ch. 
f. 537.—E. t. 311. f. 7? Triangularly orbicular equivalve, sub- 
equilateral, compressed, with numerous fine longitudinal striz 
rufous; beaks incurved and the area between them narrow ; 
within brown, the margin flattened and quite entire. 1.—Jed 
Sea. Lxtremely delicate transverse strie at intervals. 

* * With prominent radiating longitudinal ribs, either mith or 
without transverse stri@. 
P. Castaneus. Lam, 15.—W. t. 9.—Reeve. Ic. fi. 32. 
