120 CYPRINIDiE. 



centric furrows and ridges, the depressed portions wider than the 

 raised ones, vanisliing- at both ends, covered with a thick, greenish- 

 yellow or glossy, brownish-olive epidermis. 

 '" "■ Hinge-margin strong, two teeth in the left 



valve and one in the right ; interior pol- 

 ished, l)luish-white ; muscular impressions 

 distinct. Lengtli, one inch ; heiglit, one and 

 one fourth inches ; breadth, three fifths of an 

 inch. 



Dredged alive near Governor's Island, in 



A. sulcata. ^ . . x n t i i i i tt 



lour lathoms ( Nimpson) ; Marljlehcad Har- 

 l)or, at half-tide (Haskell); Halifax {Willis}; Eastport, numerous 

 and many varieties {Cooper). It is tlie most common s])ecies 

 throughout all the Northern seas. Fossil in Labrador and about 

 the Gulf of St. Lawrence {Dcnvson, Bell). 



Very small and half-grown shells arc not uncommonly found in 

 the fish of Massachusetts Bay. It has been found by dredging in 

 Newport and Portland Harbors ; and occasionally a full-grown speci- 

 men is thrown up, with sea-weed attached, on our beaches. I liave 

 no doubt it would be found in many places by dredging. Along the 

 coast of Maine it is common. At Augusta, Maine, Dr. C. T. Jack- 

 son found it ^plentifully in a partially fossilized state, and in com- 

 pany with other shells, such as are now common on the coast of 

 Maine, imliedded in the earth many feet above high-water mark, 

 showing conclusively that that region has, by some cause, been 

 recently elevated above its former level. 



This shell seems to have caused much perplexity to all who have 

 undertaken to describe it. It is quite uncertain how many real 

 species are embraced in the aljove synonymcs. The discrepancy of 

 authors, and the variety in the form and sculpture of the shells, 

 which must come under one or the otlier of the names, leaves us in 

 doubt. I have thought l)cst to present them as one, and to include 

 them under the name wliicli seems most api)ro]n-iate of the three. 

 For, in the first place, the Vemis Scotiea and V. Daimionia of Mon- 

 tagu are clearly the imnuiture and mature of the same shell ; the 

 distinctive mark which he gives, viz. the smooth margin of the first, 

 and the crenulated one of the latter, Ijeing an insufficient one. He 

 says: "The construction of the margin must be considered as invio- 

 lable ; no common shell whose character is to possess a plain margin 

 is ever f )und with a crenulated one, or vice versa.'" Now, it is per- 

 fectly certain tluit no species of the genus is found with a crenulated 



