262 NEW FOSSIL SHELLS 



lato, ad suturam lavi; basi striatd, profunde sulcatd; umbilico magno, profundo, carind marginato, intus lavi; aperturd 

 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; striae obliquely transverse, small, numerous; last whorl sometimes carinate, sometimes angulate, smooth 

 near the suture; base striate, deeply sulcate; umbilicus large, deep, margined with a carina, smooth within; mouth 

 round. 



Length .04. Breadth .10 of an inch. 



Remarks. TJie 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 stria? 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, arid in others angular and carinate. The 

 mouth is almost a perfect circle. 



The carinate umbilicus and oblique striaB separate this pretty little shell from all its 

 congeners. 



D. TROCHIFORMIS, PL. 36. FlG. 73. 



D. testa cornea, sub-lenticulari, crassd, striatd; spird sub-ovatd, obtusd, depressd; suturis canaliculatis; anfractibus tribus, 

 sub-convexis; striis Iransversis, parvis, raris; anfractu ultimo acute angulato, duplice carinato; basi striatd; umbilico parvo, 

 profundo, striis magnis marginato; aperturd sub-triangulari; labro crassissimo. 



Shell conical, somewhat lenticular, thick, striate; spire sub-ovate, obtuse, depressed; sutures canaliculate; whorls 

 three, rather convex; striae transverse, few, small; last whorl acutely angular, doubly carinate; base striate; umbi- 

 licus small, profound, margined with large striae; mouth sub-triangular; lip very thick. 



Length .08. Breadth .09 of an inch. 



Remarks. The stria3 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 

 two or three of larger size round the umbilicus. The periphery of the last whorl has 

 two carinae, 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. GLOBULUS, PL. 36. FIG. 74. 



D. testa transverse sub-globosd, crassd, canccllatd; spird planulatd, obtusd, ad apicem Icevi; suturis vix obsoletis; anfractibus 

 tribus, rapide crescentibus, supra angulatis et planulatis; costis transversis, octo, magnis; striis longitudinalibus, parvis, irre- 

 guldribus; anfractu ultimo rotundata; basi costatd et striatd; umbilico parvo, arctato; aperturd sub-rotunda, integrd. 



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; costae transverse, eight, large; striae 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 stria3, 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. 



