184 BIOLOGICAL SURVEY OF 



Periplomidae 

 Periploma Schumacher 

 P. FEAGiLis Totten. {Anatina fragilis, Totten, 1835, Amer. 

 Jour. Sci. ; Anatina papyracia, Gould, 1870, Inv. Mass., p. 66, 

 fig. 382; P. fragilis, Ball 1889, Bull. U. S. Nat. Mus.) This 

 animal, with its thin, white, fragile shell, is found generally 

 in somewhat shallow waters. Many found in fish. Stations : 

 D 2, 33, 35, 36, 38. Reported from Casco Bay, Massachusetts 

 Bay, off Block Island, Gaspe Bay, 40 fathoms ; Gulf of St. 

 Lawrence, 70 to 80 fathoms ; Chateau Bay, Labrador. Sandy 

 bottom mentioned for all localities. 



Thraciidae 

 Thracia Blainville 



T. MYOPSis Moller. (Moller, 1842, Kr0yer's Naturh. 

 Tidskr. ; T. couthouiji, Stimpson, 1851, Shells of N. E. ; T. my- 

 opsis, Gould, 1870, Inv. Mass., p. 71, fig. 385.) This is the 

 most frequent of the 3 Thracias found here, but is not a 

 common form. Stations: D 14, 22, 23, 24, 33-35, 62. Re- 

 ported from Eastport, Casco Bay, Massachusetts Bay, 

 Georges Bank, and various places along the Atlantic coast to 

 Greenland. 



T. truncata Mighels and Adams. (Mighels and Adams, 

 1842, Boston Jour. Nat. Hist. ; Gould, 1870, Inv. Mass., p. 72, 

 fig. 386.) Readily distinguished by its truncated form, this 

 species was dredged by us just inside of Mount Desert Rock, 

 but not in the Bay. Reported from Eastport, Casco Bay, 

 Massachusetts Bay, Marthas Vineyard, George Bank, off 

 Block Island, Grand Manan, Bay of Fundy, Halifax, Green- 

 land. 



T. coNRADi Couthouy. (Couthouy, 1830, Boston Jour. Nat. 

 Hist,; Gould, 1870, Inv. Mass., p. 69, fig. 384; Morse, 1913, 

 Nautilus.) This species is readily distinguished by the ab- 

 sence of teeth in the hinge. Blaney reports taking young, but 

 we did not take it. Reported from Eastport, Casco Bay, and 

 various points to Caribou. ''Burrows so deeply in the mud 

 or sand, that it is seldom taken alive in the dredge." Verrill. 



