THE ECOXOMIC MOLLUSC A OF ACADIA. 81 



15. niodiola modiolus (Lin.) Turton. 

 Mytilus modiolus, Lin. 

 Horse-Mussel. 



Modiola, a little nieasure(?); modiolus, a little measure(?). 



Distribution, (a) General; — Low-water mark to one 

 hundred fathoms. New Jersey to Arctic Ocean, and circum- 

 pohir. On European coast, southward to France; on Asiatic, 

 to northern Japan; on western American, to California. 



(b) In Acadia; — (in N. B.) Abundant on the southern 

 •coast everywhere from Grand Manan at least to St. John. 

 Shediac, Whiteaves. (In N. S.) Annapolis Basin, somewhat 

 abundant, Verkruzen. All rocky shores, Jones. (In P.E.I.) 

 Kot reported but doubtless occurs. Probably to be found in 

 rocky situations around the entire coast. 



Habits. This species more closely resembles MytilmeduUs than any 

 other Mollusc. It is generally larger than the latter, growing to a 

 length of six, and in extreme cases, mentioned by Willis, eight inches. 



Fig. 12. — Modiola modiolm. Natural size. 



It never has the blue black color of Al. eduik, but instead has an 

 ■epidermis of a dark chestnut or brown color. The umbo (or centre 

 around which the lines of growth of the shell are arranged) is at the 

 anterior or small extremity in M. edidk, but set a little back on the 

 hinge margin in this species. 



It does not, however, live in great beds above low-water mark as 

 'does M. eduUs. It prefers gravelly and stony bottoms to which, half 

 buried in the former, and half hidden in crevices in the latter, it 



