4 AMERICAN MARINE CONCHOLOGY. 
3. T. costuLatTa, Mighels and Adams. Fig. 132. 
Bost. Journ. Nat. Hist., iv. -50, t. 4, f. 20. 1842. 
Shell whitish, translucent; whorls nine or ten, nearly flat or 
very slightly convex; suture well impressed; last two whorls 
nearly smooth, the others longitudinally plicate, with microscopic 
transverse strie; last whorl subcarinate; aperture rather less than 
one-fourth the length of the shell, subovate, produced anteriorly. 
Length 17, diam. 6. mill. 
Casco Bay. 
4. T. actcuLA, Stimpson. Fig. 133. 
Bost. Proc., iv. 15. 1851. 
Shell small, turreted, subulate, white, thin; whorls ten, very 
convex, longitudinally striate and transversely ribbed; aperture 
rounded, effuse anteriorly; peristome acute. 
Length 5, diam. 1.5 mill. 
Distinguished from the young of 7. erosa by its much more 
convex whorls and prominent ribs. The operculum appears not 
to be fimbriated at its edges. 
From fishes. 
Cape Cod to Grand Manan Island. 
5. T. AREOLATA, Stimpson. 
Shells of New England, 35. 1851. 
Shell small, subperforated, turreted, red, with four distant re- 
volving elevated rips ; aperture effuse in front; lip acute; whorls 
six, convex. 
Length 5, diam. 2.5 mill. 
Probably a young shell, but appears distinct from any of our 
species. Approaches J’. reticulata, but the transverse ribs are 
more prominent, and the longitudinal ones less so than in that 
shell. Fifteen to fifty fathoms. 
Massachusetts Bay. 
This is a doubtful species. 
Genus VERMETUS, Adanson. 
Hist. Nat. Senegal, 160. 1757. 
1. V. RADICULA, Stimpson. Fig. 134. 
Shells of New England, 87. 1851. 
V. lumbricalis, Gould (not Lamarck), Invert. Mass., edit. i. 1841. 
Shell conic tubular, with numerous unequal raised lines or ribs 
along its entire length; the spiral portion consists of eight or ten 
closely revolving whorls, biangulate. 
