100 AMERICAN MARINE CONCHOLOGY. 



front ; outer lip sharp ; columella with a strong spiral fold ; oper- 

 culum hornj', elliptical, lamellar. 



Animal white ; head truncated and slighth' notched in front, 

 furnished posteriorly with recumbent tentacular lobes, and small 

 e^'es near their inner bases ; foot oblong, lateral lobes slightly re- 

 flected on the shell. 



There are few living, but over seveut}- fossil species. Distribu- 

 tion universal. 



1. T. ruNCTO-STiATA, Adams. Fig. 205. 



Bost. Journ, Nat. Hist., 323, t. 3, f. 6. 1840. 

 Shell minute, suboval, polished ; whorls four to five ; body 

 whorl large, smooth above the aperture ; beneath it, with ten to 

 fifteen punctate revolving lines ; spire short, rapidly diminishing, 

 with a shoulder near the suture ; suture deepl3' impressed ; aper- 

 ture two-thirds the length of the bodj'-whorl, becoming wider 

 beneath ; pillar lip with a prominent fold. Umbilicus open in 

 3'oung shells ; white. 



Length 2.5 to 3.T mill. 



Kcw York to Jlassachuseits. 



Genus RINGICULA, Deshayes. 

 Auim. sans Vert., viii. oil. 1838. 

 Shell small, ventricose, smooth or concentricallj' striated ; spire 

 small ; aperture with an oblique notch in front ; columella callous, 

 strongh' plicated ; outer lip thickened and reflected, with a mar- 

 ginal callus. 



1. R. NiTiDA, Terrill. 



Am. Jovnn. Sci., 16th January, 1873. 



Shell small, white, smooth, broad oval, with five whorls ; spire 

 rapidlj' tapering, subacute, shorter than the aperture ; whorls 

 verj' convex, with deep suture, and a subsutural impressed line ; 

 columella stout, recurved at the end, with two strong, very pro- 

 minent equal, spiral folds, the anterior one projecting beyond the 

 canal, with the end rounded. 



Length 4 +, diam. 3 mill. 



New England. 



Family BCLLIDJ^. 



Synopsis of Genera. 

 Shell convolute, ovate or subglobose, smooth, generally mottled ; spire in- 

 volute sunken, causing the apex to be tubular or perforate ; aperture ex- 



