44 BIVALVES MYTILUS. 



MYTILUS— Muscle. 



Animal— allied to an Ascidia: Shell bivalve^ rough, ge- 

 nerally affixed hif a h/ssus or beard of silky filaments; 

 hinge mostly without teethe with generally a subulate 

 excavated longitudinal line. 



Of the genus Mytilus there may be enumerated sixty- 

 four species ; though some of these are a httle indistinct, 

 yet the greatest proportion of them bear a near alhance 

 to tlie general form and character of the common or eat- 

 able Muscle. Tliere are, indeed, some exceptions, such 

 as may be observed in the Mytilus Crista-galli (Cocks- 

 comb Oyster), and the Mytilus Margaritiferus (true mo- 

 ther-of-pearl shell), and others of a similar description; 

 most of which give strong evidence of belonging to the 

 Ostrea or Oyster, rather than Mytilus or Muscle genus. 

 However, the hinge seems to regulate the arrangement in 

 most instances, and in the Mytilus it is usually without 

 teeth, having generally a subulate excavated line in place 

 of them. However, some have little denticulations with 

 alternate grooves, which amount in number from ten to 

 fifty in different species. The Mytilus Niger has the 

 greatest number of any, viz. one hundred. The Mytilus 

 Crista-galli and the like, affix themselves to Gorgonia 

 and other bodies, not by a beard or byssus, as is usual 

 with other Muscles, but by a formation of the shell itself, 

 which assumes the appearance of several distinct claws 

 or hands, by which the shell is secured to whatever body 

 it may have selected for its basis. 



The greatest part of this genus exhibit internally a 

 pearly appearance, and some (when uncoated and polish- 

 ed) afford the brightest radiance possible. The Mytilus 



