316 Mighels' Catalogue of 



several hours, and only ended with the ejection of the undi- 

 gested mass. I am not aware that it ever inhabits muddy 

 bottoms. 



M. grandis, Desh. ? (ovalis, Gould.) This is probably a 

 true pelagic species, as it has not been obtained anywhere in 

 New England, but from fishes' stomachs, taken in deep water. 

 Although this name, grandis, is applied to another species by 

 Deshayes, 1 prefer to retain it until the identity of our shell 

 is better settled. 



Immature specimens are frequently obtained from fishes' 

 stomachs taken in Casco Bay ; but, probably, its more conge- 

 nial habitat is much further north and east. Fine, large speci- 

 mens are sometimes obtained from the stomachs of cod-fishes 

 taken in the Gulf of St. Lawrence, but it must be regarded as 

 a rare shell. 



Genus Mesodesma. Desh. 



M. arctata, Con. Pelagic. Full grown specimens of this 

 species are occasionally found upon Saco beach, but I am not 

 aware that it is anywhere abundant in Maine. Never having 

 obtained it from the eastward, I am inclined to suspect that 

 this is nearly its utmost northern limit. 



M.jauresii, Joannis. Pelagic. 1 am not aware that this 

 rare species has ever been found in the waters of Maine, but 

 it is occasionally found in the stomachs of cod-fishes caught 

 in the Gulf ot St. Lawrence, in very deep water. 



Genus Saxicava. Lam. 



S. distorta, Lin. Say. This species, although often found 

 alive on our shores, cannot, properly, be regarded as a littoral 

 shell. Its proper habitation is, doubtless, in deep water. I 

 have, occasionally, found dwarfish and very distorted speci- 

 mens adhering to pebbles and valves of dead shells in deep 

 cavities in the ledges near Fort Preble, where the water never 

 entirely leaves them. The finest specimens I ever saw, I 

 found attached to the inside of some dead specimens of Pec- 

 ten magellnnicus, dredged by Capt. Walden in deep wa- 



