72 AMERICAN MARINE CONCHOLOGY. 



gular above, widely rounded below, slightly effuse. Lip sharp, 

 modified by the revolving lines ; the canal, an oblique fissure. 

 Operculum horny, ovate, concave externalfy, multispiral. Bluish 

 to reddish-black. 



Length 5, diam. 2.5 mill. 



Cape Cod, Mass., to NortJi Carolina. 



2. B. Greenii, Adams. Fig. 128. 



(Cerithium) Bost. Journ. Nat. Hist., ii. 287, t. 4, f. 12. 1839. 

 ? Cerithiopsis tubercularis, Mont, (sp.) 1803, teste Jeffreys. 



Shell very small, cylindrical ; beneath deeply rugose, with lon- 

 gitudinal ridges and revolving lines. Canal very deep and short, 

 slightly curved. Aperture one-eighth the length of the shell, nearly 

 circular. Reddish-brown. 

 Length 5, diam. 1.25 mill. 



Mass. to North Carolina {Eur.). 



Genus TRIPHORIS, Deshnyes. 



Animal. The tentacles are clavate at the tips, united at their 

 bases by a sinuated veil. 



The species are very numerous, inhabiting all seas, but princi- 

 pally tropical. The sculpture of the whorls is very varied, beauti- 

 ful, and constant. 



1. T. nigrocinctus, Adams. Fig. 120. 



{Cerithium) Bost. Journ. Nat. Hist., ii. 280, t. 4, f. 11. 1839. 

 Shell conic-cylindrical, with three revolving series of granules. 

 "Whorls reversed, suture broad, carinate ; aperture small, subellip- 

 tical, ending in a twisted canal about one-third as long as the 

 aperture. Reddish-black ; columella black ; a black spiral belt 

 in faded shells. 



Length 1.5, diam. 1.75. 



Massachusetts to North Carolina. 



Family Y. TURRITELLID.E. 



Synopsis of Genera. 



Shell elongated, many-whorled, spirally striated ; aperture rounded, mar- 

 gin thin ; operculum horny, many-whorled. Turritella, Lamarck. 



Shell tubular, attached ; sometimes regularly spiral Avhen young ; always 

 irregular in its adult growth ; tube repeatedly partitioned off; aperture 

 round ; operculum circular, concave externally. Vermetus, Adanson. 



