303 MYTILUS. 



Mytilus Nieobaricus, Var. Chemnitz, viii. p. 157. t. 82. 



f. 737. 

 Lister Conch, t. 357- f. IQ5 b. ? Klein Ost. t. 12. f. 76 

 and 77.? 



Inhabits the Indian Ocean. Linneeus. Coasts of the Nicobar 

 Islands. Chemnitz. China. Humphreys. 



Shell usually about two inches long, and half as broad, and has 

 a remarkably rugged appearance ; the anterior side is 

 rounded and somewhat angular, and the posterior is flattish 

 and slightly incurved ; the colour is bluish, or sometimes 

 white tinged with violet, and covered with a dark olive or 

 blackish epidermis ; the inside is sometimes dark blue, and 

 the margin is crenated. Kaemmerer has referred to Chemr 

 nitz's fig. 742. for the Linnaean M. exustus, and considered 

 fig. 736. to be a Variety of the same species. 



exustus. 19. Shell ovate-wedge-shaped, longitu- 

 dinally striated, with the anterior side angu- 

 lar ; margin crenated. 



Mytilus exustus. Linnaus Syst. Nat. p. 1156. Bom Mm. 



p. 125. t. 7-f. 5. 

 Mytilus crenatus. Chemnitz, viii. p. 165. t. 83. f. 744. 

 Lister Conch, t. 366. f. 206. Petiver Gaz. t. 153. f. 3. 



Inhabits the coasts of Jamaica. Linnaus and Lister. Tran- 

 quebar. Chemnitz. 



Shell about fifteen lines long and eight broad, of a pale fer- 

 ruginous or rose colour ; the valves are covered with very 

 fine longitudinal striae, and the margin on the inside is crenu- 

 lated. About this species a great difference of opinion has 

 prevailed, and the following of Chemnitz's figures have been 

 quoted for it ; fig. 754. (which appears to me to be the Lin- 

 naean Area modiolus) by Schroeter and Gmelin; fig. 742 

 and 743. by Chemnitz and Kaemmerer ; Schroeter and 

 Gmelin, with a mark of doubt, have quoted Chemnitz's fig. 

 744. and Born's figure for M. stria tulus of the Mantissa, 

 but the present is a larger and broader shell, and is rather 

 convex on both sides. 



striatulus. 20. Shell very finely striated longi- 

 tudinally, with the anterior side slightly an- 

 gulated, and the other incurved ; stria? slightly 

 crenated. 



- Mytilus striatulus. Linnaus Mantissa, p. 548. Schroeter 

 Einl. iii. p. 449. t. 9. f. 16. Gmelin, p. 3358. 



