300 MYTILUS. 



Ostrea. Enc. Method, t. 185. f. 9- 



Rumphius, t. 47- f. D. Petiver Amb. t. 20. f. 2. Gual- 

 ter, t. 104. f. E. Jrgenville, t. 23. f. D. Knorr, iv. t. 

 10. f. 3 to 5, and v. t. 16. f. 1, and t. 17. f. 1 to 3. Re- 

 genfuss, ii. t. 2. f. 16. Favanne, t. 45. f. A 3. 



Variety. With the shell reversed. 



Ostrea Crista-galli sinistra. Chemnitz, ix. p. 140. t. 1 16. 

 f. 998. 



Inhabits the Indian Ocean, adhering to Gorgoniae. Linnaus. 

 Amboyna. Rumphius. Red Sea, and coasts of the Mo- 

 lucca Islands, and Coromandel. Chemnitz. China. Hum- 

 phreys. Has been found alive adhering to the bottoms of 

 ships on the coast of Britain. Montagu. 



Shell sometimes two inches and a quarter long, and nearly two 

 inches and three-quarters broad, but is usually smaller ; the 

 valves are transversely rugged, and strongly plaited longitu- 

 dinally, with sharp angular plaits which correspond with each 

 other, so as to shut close at the margin ; the colour varies 

 from dark purplish brown to pale chestnut, and the inside is 

 yellowish. The animal, the hinge, and the muscular im- 

 pressions are similar to those of the Ostreae, and whenever 

 the Genera are new modelled, this species, and also M. 

 Hyotis and M. From must be removed. 



hyotis. 2. Shell oval, plaited, and imbricated with 

 broad compressed spinous membranes ; both 

 lips smooth. 



Mytilus Hyotis. Linnaus Syst. Nat. p. 1155. Bom Mas. 



p. 122. Schroeter Einl. iii. p. 423. Gmelin, p. 3350. 

 Ostrea Hyotis. Mus. Gevers. p. 424. So/ande?-'s MSS. 



Portland Cat. p. 6. lot 80. Callone's Cat. p. 53. No. 



1012. Chemnitz, viii. p. 58. t. 75. f. 685. 

 Ostrea. Enc. Method, t. 1 86. f. 1 and 2. 

 Rumphius, t. 47. f. C. Petiver Amb. t. 20. f. 5. Gualter, 



t. 103. f. A. Argenviile App. t. 3. f. F. Knorr, i. t. 



29. f. 1. Favanne, t. 45. f. C. 

 Inhabits the Indian Ocean adhering to Gorgoniae. Linnaus. 

 Coasts of Amboyna. Rumphius. China and the Friendly 

 Islands. Humphreys. 

 Shell about four inches and a quarter long, and three inches 

 and a quarter broad, of a dark brownish olive, or ferruginous 

 colour; the valves are strongly plaited longitudinally, and 

 covered with imbricated transverse scaly membranes, here 

 and there beset witk thick hollow thorn-like processes. 



