OSTREA. 267 



Shell from one to two inches long, and the breadth rather ex- 

 ceeds the length ; it is nearly allied to O. operculum, but 

 differs in having a slightly elevated red line on the ridge of 

 every rib of the upper valve, without any other coloured 

 marking. 



nucleus. 44. Shell sub-orbicular, with about twen- 

 ty transversely wrinkled ribs, and the margin 

 strongly plaited. 



Ostrea nucleus. Born Mm. p. 107- t. 7. f. 2. 



Ostrea Tranquebarica. Gmelin, p. 3328. 



Ostrea, No. 19. Schroeter Einl. iii. p. 330. 



Ostrea undata. Born Mm. p. 108. 



Lister Conch. 1. 179- f. 16. Guulter, t. 73. f. L and M. 



Knorr, ii. t. 4. f. 2 and 3. Enc. Meth. t. 212. f. 4. 



Inhabits the East Indies. Lister. Coasts of Tranquebar, 

 Chemnitz. 



Shell about an inch and a quarter long, and the breadth a trifle 

 exceeds the length ; it has about twenty elevated ribs, and is 

 delicately wrinkled transversely ; the colour is white, and the 

 flattest of the valves is mottled or otherwise variegated with 

 brown, red, or grey ; of the auricles one is rectangular, and 

 the other in one valve is dilated ; but in the other valve they 

 are so nearly equal, that if examined separately the species 

 might be referred to the first subdivision, and corresponds 

 with the Linnaean description of O. minutu. 



gibba. 45. Shell sub-orbicular, gibbous, with about 

 twenty longitudinal striated ribs, and slightly 

 wrinkled transversely ; smaller auricle ob- 

 lique. 



Ostrea gibba. Linnaus Syst. Nut. p. 1147. Born Mm. 



p. 107. Schroeter Bird. iii. p. 318. Gmelin, p. 3325. 

 Ostrea lutea. Gmelin, p. 3320. 

 Ostrea plana. Gmelin, p. 3320. 

 Ostrea flabellum. Gmelin, p. 3321. 

 Ostrea, No. 45. Schroeter Einl. iii. p. 339, No. 53. p. 



340, and No. 82. p. 348. 

 Pecten rubicundus. Chemnitz, vii. p. 321. t. 65. f. 6 19 



and 620. 

 Gualter, t. 73. f. D and F, and t. 74. f. I. Browns Ja- 



muica, t. 40. f. 10. Knorr, i. t. 18. f. 2, ii. t. 5. f. 4, 



and t. 17. f. 2, and v. t. 13. f. 9- Regenfuss, i. t. 1. 



