TRIBE MALLEACEA, 259 
the original type in the Parisian Museum, which is the fac-simile 
of Linneus’s own specimen of Ostrea Perna. 
P. Vursevia. Lam. 9.—List. t. 199. f. 33. Elongated, tongue- 
shaped ; hinge-margin short, oblique, with but few teeth; beaks 
small, hooked. 23}. Indian Seas. The original specimen which I 
saw in the Museum at Paris appears a young shell. 1 
P. Listert. Nobis.—List. t. 228. f. 63.—Klen. t. 8. f. 19. 
20. Subovate, longer than broad, rather irregular in shape, ine- 
quivalve, with undulated slightly elevated radiating ribs, which are 
not crowded, either rayed with purplish brown on a pale yellowish 
ground or vice versa; dorsal edge moderately long; posterior 
sinus short and deep, in one valve only; posterior edge obliquely 
rounded, the shell being produced anteriorly ; anterior edge nearly 
straight.14. W. Indies. The figures of Lister and his copyist Klein 
are quoted for Sulcata by Lamarck. The shell from which that species 
was described, is very different from this, and easily to be distin- 
guished by its difference of colouring and its narrow crowded riblets. 
In all specimens of Listeri examined by myself, the colouring matter 
is confined to the upper valve. 
P. Nuctevs. Lam. 10. Small, oval, rather acute at the base; 
posterior side with almost two sinusses: hinge with four teeth 
or with a fifth obsolete one. 2 Isle of St. Francis and St. Peter, 
Australia. 
P. Lecumen. Lam. 12.—Ostrea L. Gmet. 3399.—D. p. 283. 
—Ch. f. 578.—E. t.175. f. 23.—W. t. 11. f. 83. Longitudi- 
nally linear, straight, very brittleand diaphanous, yellowish white ; 
the hinge oblique, with but few teeth. Nicobar Isles. 1}..+4. 
P. Costetnata. Conr. Jour. Philad. 7. p. 246. Very much 
elongated longitudinally, and greatly compressed, yellowish white, 
with radiating tuberculated strie. 2} Sandwich Isles. 
P. Incisa. Conr. J. Philad. 7. t. 19. f. 9. Longitudinally 
subovate, dilated towards the ventral edge which is arcuated and 
bordered by obsolete radiating striz, dark purplish brown; the 
hinge margin rather short, with from three to five teeth, posterior 
sinus short and deep; anterior side subauriculated, the edge 
nearly straight, inclined to convex: within highly polished, pale, 
variegated with dark purplish brown. 2. Sandwich Isles. Allied 
to Obliqua. 
P. Cauirornica. Conr. J. Philad. 7. t. 19. f. 13. Compressed, 

1 The variety of Lamarck. Ch. f. 579.—Coped E. t. 175. f. 1. 
which is adorned with broad red rays, is separated justly by Desh- 
ayes and Anton; by the latter it is entitled Radiata. It comes 
from the Indian Seas and is represented as rather more than two 
inches long. 
s.2 
