De TESTACEOUS MOLLUSCA. 
angularly ovate, oblique; with transverse erect and reflected 
lamellze : interstices very finely striated: two teeth in one valve 
and one in the other. %.— Mediterranean. 
P. Ocuroxevca.* Lam. 2.—Tevuina Fraciuis. Lin. 1117.— 
D. p. 78.—Ch. f. 84.—Payr. t. 1. f. 9, 10.—Wood. sup. Tel. 
Jj. 6. Thin, irregularly ovate, yellowish white, with rather distant 
transverse striz and finer vertical ones in the interstices ; two 
teeth in one valve and a heart-shaped one in the other.—Wediter- 
ranean and European Seas. 
P. Semiznameuuata. Lam. 3.— Del. t.4.f. 10. Small, semi- 
transparent, thin, white, triangularly ovate, anteriorly rather 
flexuous, with rather distant transverse grooves, the upper ones of 
which are lamellar, interstices longitudinally striated ; two teeth in 
one valve and one in the other.— Rochelle. 
P. Luctnatis. Lam. |.—VeEnus Divercens. G'mel. 3269.— 
D. p. 191.—Ch. f. 1666, 7.—W. t. 8. f. 73. Suborbicular, in- 
flated, the ventral margin somewhat depressed, with transverse 
arched and other intervening variously curved striz ; two teeth in 
one valve and one in the other.— Nem Holland. 
P.Srraiatra. Lam. 5.—Del. t. 4. f. 11. Triangularly ovate, 
rounded at both ends, with close longitudinal grooves and a few 
transverse strie ; anterior side compressed ; umbones prominent : 
two teeth in one valve and a cleft one in the other.— Rochelle and 
Corsica. 
P. CosteLtata. Lam. 6.—Del. t. 4. f. 12. Inflated, trian- 
gular, ovate, rounded at both ends, dirty white, with numerous 
longitudinal waved subacute rib-like strize ; a large and two small 
teeth in one valve.— Mediterranean. 
P. Rocceiuaria. Lam. 7.—Del.t.4. f. 13.—Poli. t.7. f. 14, 
15.2? Triangularly ovate, radiatingly wrinkled by longitudinal 
grooves, a few transverse strie : hinge with two teeth in one valve 
and an obsolete one in the other.— Rochelle and Mediterranean. 
— Closely resembling Striata, but not so elongated anteriorly. 
P. Ruperetta. Lam. 9.—E. 3. p. 747.—Del. t. 4. f. 14. 
Ovate-triangular, the posterior side inflated and smooth, the an- 
terior longitudinally wrinkled ; two teeth in each valve, of which 
one, at least, is bifid.— Rochelle.—Variety, with longitudinal 
grooves.— Bayonne.— Very like Striata, but ventrally sinuated. 
P. Puorapirormis. Lam. 11.—Sow. G. f. 1, 2.—£. vol. 3. 
p- 747.—Reeve. t. 51. f. 1.—Gould. p. 53.—P. Fornicata. Say. 
Transversely elongated, white; the posterior side very short and 
covered with toothed lamellar longitudinal grooves; anterior side 
nearly smooth and slightly gaping; ventral margin slightly in- 
curved: valves with two cardinal teeth. 14.— Rhode Island. 
P. Fasacetia. Lam. 12. Oval, decussated by fine longi- 
tudinal and transverse strie.— New Holland in Madrepores. 
