ACEPHALA. 23 
(Migh.) Mass. Bay, (W. 8.) Off Martha’s Vine- 
yard, (Ag.) Off coast of Long Island, in 38 f. (C. 8.) 
T. Cournouyi, St., Bost. Proc. iv. 8.1851. T. parva, 
alba, solidula, orbiculato-ovalis, sub-quilateralis, 
compressa, antice angustior, rotundata; postice laté 
truncata; striis concentricis inequalibus rugosa ; 
sinus siphonalis latus. Ossiculum minutissimum. 
Long. .7, lat. .54, poll. 
Corall. Eastport, Me., and Mass. Bay. 
T. Conrap1, Couth. Gould, 50.— Lamin. Whole 
Coast. Eastport, in 6 f. (W. 8.) The absence of 
an ossiculum in this species, (which is found in the 
two preceding species,) would seem suflicient to sep- 
arate it generically from other Thracie. But the ani- 
mal resembles so closely that of the large English 
species which possess the ossiculum, that I have 
thought it best to consider the appendage unimpor- 
tant. 
PANDORID. 
Lyonsta HyaLIna, Con. Ostesdesma hyalina, Couth. 
Gould, 46, f. 31.— Lamin. Whole Coast. 
PANDORA TRILINEATA, Say. Gould, 44.— Laminarian. 
Whole Coast. Eastport Harb. 5 f. mud, (W. 58.) 
Portland Harb. (Migh.) Salem Harb. in 1 to 6 f. 
(Wh.) Boston Harb. in 4 f. shelly ground, (W. 8.) 
Nantucket at low water, (Parker.) Vineyard Sound, 
(Ag.) Buzzard’s Bay in 8 f. (Prime and W. 8.) 
