THE NAUTILUS. 1 13 



THE SHELL-BEARING MOLLUSCA OF EHODE ISLAND. 

 BY HORACE F. CARPENTER. 



[Continued. ] 

 Genus Pecten Brug. 1789. 

 The pectens, fan-shells or scallops have on each side of the beaks 

 a broad expansion of shell called ears; beaks touching; hinge tooth- 

 less, with a triangular pit for the cartilage. The animal has no 

 syphons; the mantle is free, its margins double, the inner one 

 fringed and hanging down like a curtain, and the outer one with a 

 row of dots shown to be eyes. They move about very rapidly by sud- 

 denly opening and shutting, their valves, and can jump two or three 

 feet; they seem to have the power of choosing the direction, for they 

 can, by a sudden jerk, jump backwards or to either side, skip along 

 the surface of the water or sink to the bottom. I never saw one 

 jump forwards. AVe have in New England three species, two 

 of which inhabit Rhode Island. 



208. Pecten irradians Lam. 



Syn.: Pecten concentricus Say, Con., DeKay, Gld. 



Shell nearly round ; valves convex, with about twenty elevated, 

 rounded ribs radiating from the beaks, the ribs and spaces between 

 of nearly equal breadth ; ears nearly equal ; interior shining ; on the 

 exterior the ribs and spaces are both rounded while on the interior 

 the corresponding spaces are flat. Length three inches, height two 

 and a half, breadth one. The so-called eyes in this species, of which 

 there are from forty to sixty, situated along the edges of the mantle 

 in both valves, are of a beautiful bright-blue color. This is the 

 common scallop and is a very abundant shell in Rhode Island, but 

 owing to the great demand for this luscious bivalve in the market, 

 the State of Rhode Island has passed laws prohibiting their being 

 taken through the summer months of each year. The "scallop law " 

 is off on the first day of September, and on the morning of that day 

 hundreds of boats may be seen in our waters at sunrise eager to be 

 first on the grounds where the scallop beds are. Thousands upon 

 thousands of bushels of pectens are dredged during the following 

 three or four months, and if it were not for the law allowing the 

 young a chance to get their growth, one season would completely 

 exhaust the supply. The entire animal is not used for food, like the 



