100 AMERICAN MARINE CONCHOLOGY. 
front; outer lip sharp; columella with a strong spiral fold; oper- 
culum horny, elliptical, lamellar. 
Animal white; head truncated and slightly notched in front, 
furnished posteriorly with recumbent tentacular lobes, and emall 
eyes near their inner bases; foot oblong, lateral lobes slightly re- 
flected on the shell. 
There are few living, but over seventy fossil species. Distribu- 
tion universal. 
1. T. puncto-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 deeply impressed ; aper- 
ture two-thirds the length of the body-whorl, becoming wider 
beneath; pillar lip. with a prominent fold. Umbilicus open in 
young shells; white. 
Length 2.5 to 3.7 mill. 
New York to Massachusetts. 
Genus RINGICULA, Deshayes. 
Anim. sans Vert., viii. 841. 1838. 
Shell small, ventricose, smooth or concentrically striated ; spire 
small; aperture with an oblique notch in front; columella callous, 
strongly plicated; outer lip thickened and reflected, with a mar- 
ginal callus. 
1. R. nrripa, Verrill. 
Am. Journ. Sci., 16th January, 1878. 
Shell small, white, smooth, broad oval, with five whorls; spire 
rapidly tapering, subacute, shorter than the aperture; whorls 
very 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 BOLLID. 
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- 
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