182 NEW-YORK FAUNA— MOLLUSCA. 
MytTILus BOREALIS. 
PLATE XIll. FIG. 222. 
(STATE COLLECTION.) 
Mytilus borealis. Lam. An. sans vert. Vol. 3, p. 21, No. 25, Ed. Brux. 
M. edulis, | Gouxp, Invertebrata of Mass. p. 121, fig. 82. 
Description. Shell solid, elongate, subtriangular, somewhat ventricose, smooth, shining, 
flattish on the posterior and somewhat angulated and keeled on the anterior margin. Beaks 
tumid, pointed. Hinge an inch long, with numerous tooth-like elevations and cavities. Basal 
margin curved and scooped out, with a small fissure for the passage of the byssus. 
Color. Black or greenish black; within blue-black on the margin; purplish and bluish 
white in the cavity. 
Length, one to two and a half inches. 
This species is common on the northern seacoast of the United States. On the coast of 
Long island it is used to some extent, as well as the M. plicatula, as a manure, for which 
eighteen cents per bushel is paid. 
We follow Lamarck in considering this as distinct from the common edulis of Europe, with 
which, however, it is closely allied. In several specimens, it may admit of doubt whether 
the beaks are even terminal. There is a variety. 
Myritus NOTATUS. 
PLATE XIII. FIG. 223. 
(STATE COLLECTION.) 
Description. Shell oblong, oblique, with minute concentric strie, smooth, compressed, 
angulated on the anterior side, regularly rounded on the basal margin, which is entire; the 
posterior margin slightly plicate. Beaks distinct, contiguous, terminal: a small bifid tooth 
under the beak, received into a corresponding depression in the other valve. 
Color. Reddish brown, with deep purple zigzag marks; posterior surface chesnut-brown ; 
within bluish purple, iridescent. 
Length, 1-7. Width, 0°8. 
I am not sure whether the following species, which is regarded by some conchologists as a 
variety of borealis, may not be identical with notatus. 
