CEEPIDULA. 273 



Sowerbj. Deshayes observes tbat he can hardly thhik tliat the 

 shell figured as Cahjplrcca xuiguiformis by Broderip, in " Trans. 

 Zool. Soc." i. pi. 29, fig. 4, is the shell of LimifBus. He says the 

 shell of Linnaeus is distinguished by a profound notch at one extrem- 

 ity of the partition, and a feebler one at the other ; that the shell 

 described by Mr. Say as Crcpidiila plana wants this notch, and is 

 the shell figured by Broderip. Now it so happens, that the only 

 specimen which I am certain is entire has this notch precisely as 

 described, and the tooth-like process which separates the large notch 

 from the rest of the margin is such as would be likely to be broken 

 in almost every instance. This fact leads me to suppose, that all 

 three of the shells in question are of the same species, and should 

 be called C. nnguifonnis. If so, its habitat is as wide as that of C. 

 fornicata. But as I have not yet the means of confirming my sup- 

 position, I give Mr. Say's name.* 



Whole Atlantic coast of the United States. 



Crepidula convexa. 



Fig. 15. 



Shell elevated, apex terminal, separated from the body of the shell ; diaphragm 

 convex, less than half the aperture, edge simple. 



Crepidula convexa, Sat, Journ. Acad. Nat. Sc. ii. 227 (1822) ; ed. Binxey, 75. — Gould, 

 Inv. 1st ed. IGO, fig. 15. -De K.\y, N. Y. Moll. 158, pi. 7, fig. 131. — Stimpson, 

 Check Lists, 4. 



Shell small, opaque, very convex, obliquely-ovate, one side nearly 

 vertical, the other sloping ; surface wrinkled, color ashen-brown, 

 with bands, stripes, or dots of dark reddish-brown ; apex 

 acute, separate from the body of the shell, turning very 

 little to one side, and downwards as far as the tip of the 

 shell ; within shining, of a uniform dark reddish-brown 

 color ; aperture oval ; diaphragm deeply situated, leaving 

 a cavity extending into the beak, convex, brown, the free 

 edge white and simply curved. Length, nine twentieths of 

 an inch ; l)rcadth, six twentieths of an inch ; height, four twenti- 

 eths of an inch. 



Found on sea-weed, and on stones among the roots of sea-w^eed. 

 Massachusetts Bay, southward {Stimpson) ; Sable Island (^Willis). 



It is seldom found entire. Mr. Say described from dead shells, 

 and had not seen its true colors. In most instances one side is 



* It is now acknowledged to be the ungulformis. — W. G. B. 

 18 



