44 AMERICAN MARINE CONCHOLOGY. 
arched, lip simple; fulyous brown or light-reddish bay, marked, 
more or less plentifully, with white lunate spots, interior of the 
aperture bluish-white or brownish. 
Length 64, diam. 43 inches. 
Southern Coast, W. Indies. 
Genus CERITHIOPSIS, Forbes and Hanley. 
Brit. Moll., iii. 364. 1853. 
Shell turreted, many-whorled, dextral, granulated; aperture 
subrotund ; inner lips broadly reflected ; outer lip acute, arcuated 
and produced anteriorly; aperture anteriorly sinuated; canal 
short. Operculum corneous, concentric, nucleus terminal. 
1. C. Emersonu, Adams. Fig. 71. 
(Cerithium.) Bost. Journ. Nat. Hist., ii. 284, t. 4, f. 10. 
Shell long, conical; whorls seventeen, flat, each with three rows 
of granules; suture very deeply impressed; aperture small, sub- 
quadrate, about one-sixth the length of the shell; columella 
spirally twisted; canal less than half the length of the aperture. 
Color dark reddish-brown. 
Length 13, diam. 3 mill. 
Animal with a long small foot, truncate in front, and notched 
behind, pale with white flecks; head broadly rounded, dark flesh- 
color in front. 
New England. 
2. C. TEREBRALIS, Adams. Fig. 72. 
Bost. Journ. Nat. Hist., iii. 320, t. 8, f. 7. 1841. 
Elongated; whorls ten to twelve, flattened, with three or four 
elevated revolving ridges on each, with numerous fine longitudinal 
lines between the ridges. Base abrupt; aperture oval, about one- 
eighth of the total length of the shell. Color reddish-brown. 
Length 12, diam. 3 mill. 
Animal whitish, with flakes of opaque-white, tentacles clouded 
Massachusetts. (Eur.) 
According to Gwyn Jeffreys this is a synonym of frilineata, 
Phil. (1836). 
Genus ACUS, Humphrey. 
Mus. Calonn. 1797, 
Terebra (part.). Lamarck, Prodr. p. 71. 1799. 
Shell subulate, solid, porcellanous; whorls numerous, simple ; 
aperture small, emarginate anteriorly, not produced into a canal; 
