MUSCLE. 
GENERIC CHARACTER. 
Shell bivalve ; frequently adhering to some substance by 
a beard. 
Hinge without teeth, the valves being merely united by 
cartilage* 
SPECIFIC CHARACTER. 
Mytilus margaritiferus. M. testa compresso-plana subor- 
biculata, basi transversa imbri- 
cata, tanicis dentatis. Linn. Syst. 
Nat. Gmel. 1. p. 3351. 
A compressed suborbicular shell, 
transversely imbricated at the 
base, and toothed on the outside. 
Matrix Perlarum. Rumph. Mus. 
pi. 47. f. F. 
Gallina guttata. Argenv. Conch. 
pi. 20. f. A. 
Pearl Muscle. .... List. Conch, pi. 221. f. 56. Gualt. 
Test. pi. 84. f. E. F. G. Chemn. 
Conch. 8. pi. 8. fig 7^7 — 721 -a. b. 
This muscle has become of consequence on ac- 
count of the valuable concretion which is occasion- 
ally found adhering to the inner coat of its shell: 
2 0 2 
