CHAM A. 21 J 



form, and has a large ovate aperture by the hinge ; the mar- 

 gin is toothed and crenated. Under all its different appear- 

 ances it may be at once distinguished from C. Hippopus by 

 the aperture in its posterior slope. Large pearls are occa- 

 sionally found in this species, and one exhibited at Sir Jo- 

 seph Banks's in June, 1814, was valued at between 200 and 

 300^. 



hippopus. 4. Shell longitudinally plaited, ribbed, 

 and muricated ; posterior slope heart-shaped, 

 closed, and the margin toothed. 



Chama Hippopus. Linmeus Si/st. Nat. p. 1137. Bom 

 Mus. p. 81, and Vign. at. p. 79- Chemnitz, vii. p. 127. 

 t. 50. f. 493 and 499. Schroeter Einl. iii. p. 232. Gme- 

 lin, p. 3300. Brooks 's Introd. p. 70, t. 3. f. 32. 

 Hippopus maculatus. Lamarck Syst. des Anirn. p. 117. 

 Tridacna. Enc. Method, t. 236. f. 2. 

 Bonanni Rec. 2. f. 81 and 82, and Kirch, f. 80 and 81. 

 Lister Conch, t. 349. f. 187, and t.350. f. 188. Rum- 

 phius, t. 43. f. C. Petiver Amb. t. 18. f. 15. Gualter, 

 t. 93. f. A. Argenville, t. 23. f. H. Knerr, i. t. 22. 

 f. 1 and 2, and vi. t. 9. f. 3. Regenfuss, i. t. 10. f. 49- 

 Da Costa Elements, t. 7- f. 10. Favanne, t. 51. f. F. 

 Inhabits the East Indian Ocean. Lister. Coasts of Amboyna. 



Rumphius. China, and Java. Chemnitz. 

 Shell commonly about two inches long, and three inches and a 

 quarter broad, but is sometimes twice as large; it is remark- 

 ably thick and heavy for its size, and the colour is white or 

 yellowish, with scattered reddish or purple spots. 



plumbea. 5. Shell sub-orbicular, solid, tubercu- 

 lated, and coated with a brown epidermis; 

 apices recurved, and the margin entire. 



Chama plumbea. Chemnitz, xi. p. 237. t. 203. f. 1991 

 and 1992. 



Inhabits the South Sea. Chemnitz. 



Shell about an inch and three quarters in diameter, thick, solid, 

 and has the whole outer surface knotty or tuberculated ; the 

 hinge has its primary tooth very strong, and the fossule cre- 

 nated. 



antiquata. 6. Shell somewhat heart-shaped, with 

 convex longitudinal ribs, and striated trans- 

 versely ; posterior depression cordiform. 



