TRIBE MALLEACEA. 259 



the original type in the Parisian Museum, which is the facsimile 

 of Linnceus's own specimen of Ostrea Perna. 



P. Vulsella. Lam. 9. — List. t. 199./. 33. Elongated, tongue- 

 shaped ; hinge-margin short, oblique, with but few teeth ; beaks 

 small, hooked. 2\. Indian Seas. The original specimen which I 

 saw in the Museum at Paris appears a young shell, l 



P. Listeri. Nobis.— List. t. 228. f. 63.— Klein, t. 8. /. 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. 1 \. 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. Nucleus. 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. § Isle of St. Francis and St. Peter s 

 Australia. 



P. Legumen. Lam. 12.— Ostrea L. Gmel. 3399. — D. p. 283. 

 —Ch.f. 578.—E. t. 175. f. 23.— W. t. 11. /. 83. Longitudi- 

 nally linear, straight, very brittleand diaphanous, yellowish white ; 

 the hinge oblique, with but few teeth. Nicobar Isles. 1 \. .-J. 



P. Costellata. Conr. Jour. Philad. 7. p. 246. Very much 

 elongated longitudinally, and greatly compressed, yellowish white, 

 with radiating tuberculated striae. 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 striae, 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. Californica. Conr. J. Philad. 7.t. 19. f. 13. Compressed, 



1 The variety of Lamarck. Ch. f 579.— Copied 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 



