262 NEW FOSSIL SHELLS 
lato, ad suturam lav; basi striaté, profundé sulcatd; umbilico magno, profundo, carind marginato, intus levi; apertura 
rotunda. ; 
Shell orbicular, depressed, thick, diaphanous, sub-cancellate; spire very short, ovate, longitudinally and deeply 
sulcate near the apex; sutures impressed, linear; whorls four, convex; sulculi longitudinal, nearly obsolete at the 
lower suture; strize obliquely transverse, small, numerous; last whorl sometimes carinate, sometimes angulate, smooth 
near the suture; base striate, deeply suleate; umbilicus large, deep, margined with a carina, smooth within; mouth 
round, 
Length .04. Breadth .10 of an inch. 
Remarks.—The longitudinal sulci are quite large on the upper whorls, but become 
smaller and closer as they approach the last whorl, while on the base they again increase. 
The strie are very oblique, but are more nearly transverse than longitudinal. On the 
last whorl, they form cancellations with the sulci, and are obsolete near the suture as 
they approach the mouth. ‘The umbilicus is carinate and scalariform, decreasing from 
whorl to whorl in rectangular steps. ‘The periphery of the last whorl is extremely vari- 
able, being in some specimens almost round, and in others angular and carinate. The 
mouth is almost a perfect circle. 
The carinate umbilicus and oblique striw separate this pretty little shell from all its 
congeners. 
D. TrocHirormis, Pui. 36. Fia. 73. 
D. testé conicd, sub-lenticulari, crassd, striatd; spird sub-ovatd, obtusd, depressd; suturis canaliculatis; anfractibus tribus, 
sub-convexis; strtis transversis, parvis, raris; anfractu ultimo acute angulato, duplicé carinato; basi striata; umbilico parvo, 
profundo, striis magnis marginato; apertura sub-triangulart; labro crassissimo. 
Shell conical, somewhat lenticular, thick, striate; spire sub-ovate, obtuse, depressed; sutures canaliculate; whorls 
three, rather convex; striw transverse, few, small; last whorl acutely angular, doubly carinate; base striate; umbi- 
licus small, profound, margined with large striw; mouth sub-triangular; lip very thick. 
Length .08, Breadth .09 of an inch. 
Remarks.—The strie on the upper part of the last whorl are few in number and very 
faint; on the base, however, they are more numerous and deeper. There are usually 
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two or three of larger size round the umbilicus. ‘The periphery of the last whorl has 
two carine, one upon the angle, and one immediately above it. On the superior whorls 
these are both hidden. 
This shell, in outline, seems rather to be a Trochus than a Delphinula. Its spire is 
very much elevated, and its umbilicus unusually small for this genus, but the entire 
margin of the mouth is a character too well marked to be neglected. 
D. ciopuLus, Pr. 36. Fia. 74. 
D. testé transverse sub-clobosd, crassd, cancellatd; smrd planulatd, obtusd, ad apicem levi; suturis vic obsoletis; anfractibus 
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tribus, rapide crescentibus, supra angulatis et planulatis; costis transversis, octo, magnis; strits longitudinalibus, parvis, irre- 
guldribus; anfractu ultimo rotundata; basi costatd et striata; wmbilico parvo, arctato; aperturd sub-rotunda, integra. 
Shell transversely sub-globose, thick, cancellate; spire flattened, obtuse, smooth at the apex; sutures nearly obso- 
lete; whorls three, rapidly increasing, angular and flattened above; coste transverse, eight, large; strie longitudinal, 
small, irregular; last whorl rounded; base costate and striate; umbilicus small, narrow; mouth sub-rotund, entire, 
Length .15. Breadth .18 of an inch, 
Remarks.—The longitudinal strie, or lines of growth very frequently do not cross the 
ribs. The mouth is slightly quadrate. The sculpture is not unlike that of the Acteon 
globosa, herein described. 
