GASTEROPODA. 37 
with few distant ribs. 2d. The anterior half of this 
form, left by the decadence of its posterior half, with 
a part of the growing adult shell. 3d. The adult 
form. 'Thus septa would appear to be thrice formed. 
This species inhabits the Laminarian zone in New 
Bedford Harbor, where it was dredged adhering to 
groups of Vermeti. (W. 8.) 
CERITHIADA. 
APORRHAIS OccIDENTALIS, Beck. fostellaria occiden- 
talis, Gould, 298, f. 205.— Corall. Off Campo-bello, 
in 50 f. mud, (W. 8.) Isles of Shoals, in 20 f. sand, 
(Wh.) 
Crerituium Sayt, Menke. Gould, 278, f. 183.— Litt. 
From Cape Cod southward. 
C. Greenu, Adams. Gould, 279, f. 184.— Lamin. 
Boston Harb., 3 f. (W. 8.) and southward. 
C. nigrocinctum, Ad. Gould, 277, f. 182.— Lamin. 
From Buzzard’s Bay southward. 
VERMETIDA. 
VeERMETUS RADICULA, St. V. lumbricalis, Gould, 246. 
(non Lam.) — Lamin. From Buzzard’s Bay south- 
ward. 
This species may very probably be identical with 
V. bicarinatus, or V. Knorrii of Deshayes, or more 
properly, perhaps, they are all varieties of one species. 
Specimens from Buzzard’s Bay agree with those 
from N. C., and differ from the West Indian shells, 
