shell; covered with many distinct, nearly equal, concentric, smooth
ridges; the front part of the ridges somewhat elevated, thin, hinder part
distinctly lamellar and much elevated: the lunule subulate, lanceolate;
the edge quite entire; umbones with a purple spot; inside white, except
on the anterior and posterior dorsal edges, which are purple; length
eight-tenths, height six-tenths of an inch.

There are two other specimens of this shell in the Museum which do not
agree with any that Lamarck describes; one of these being fourteen-tenths
of an inch long, and one inch high, is double the size of Captain King's
specimen; its habitation is not marked, but the other specimen is from
Ceylon.

10. Cytherea kingii (n.s.)
Testa ovato-cordata, tumida, albida, concentrice substriata, radiata,
radiis flavicantibus; lunula lanceolato-cordata; intus albida.

Shell ovate, heart-shaped, white or pale brown, with darker brown rays,
each formed of several narrow lines, the umbones white, the edge quite
entire; the lunule lanceolate heart-shaped, obscurely defined, the centre
rather prominent; inside white, the hinge margin rather broad.

This shell is very like Cytherea loeta, but differs from it in its
markings, as well as its outline, which is more orbicular. The specimen
given to the Museum by Captain King, is one inch long, and eight-tenths
of an inch high; but there is another specimen in the collection, from
the Tankerville cabinet (Number 288) which is twice that size.

11. Cytherea gibba.
Cytherea gibbia, Lam. Hist. 5 577.
Icon. Chemn. 7 t. 39. f. 415. 416.

12. Petricola rubra ? Cardium rubrum ? Montague.

This shell agrees in general form, teeth, and colour, with the Cardium
rubrum of Montagu, but it is larger. It was found imbedded in the seaweed
and spongy-like substance that covers the Tridacna squamosa.

13. Chama limbula, Lam. Hist. 6 95.

This shell may, perhaps, be a variety of Chama gryphoides.

14. Tridacna gigas, Lam. Hist. 6 pt. 1. 105.
Chama Gigas, Gmel. Syst. Nat. 1 3299.
Icon. Chemn. 7 t. 49. f. 495. Ency. Meth. plate 235. f. 1.

15. Pectunculus radians ? Lam. Hist. 6 54.

16. Arca scapha, Lam. Hist. 6 42.
Icon. Chemn. 7 201. t. 55. f. 548. Ency. Meth. plate 306. f. 1. a, b.

17. Mytilus erosus, Lam. Hist. 6 pt. 1 120.

This shell was described by Lamarck from some New Holland specimens, that
were probably collected by Peron in Baudin's voyage. It is remarkable for
being very thick and solid,