152 UNITED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. 



though the tendency of opinion seems to be toward the adoption of such a 

 rule, which I am inclined to favor, The reason for doubts, however, in this 

 case, is, that Venilia of Duponchel itself, may prove to be a synonym. At 

 least, some eminent entomologists regard it as synonymous with Pseudopan- 

 thera, Hiibner, 1816; Zerene, Treitschke, 1825; and Melanippe, Boisduval, 

 1S'29; but many others consider it a good and distinct genus. If it should 

 fall into synonymy, however, this would leave Morton's name to stand for the 

 genus of shells under consideration, according to the rule followed by many 

 naturalists. 



In regard to the geological range of this genus, it may be remarked 

 that the section Venilicardia seems to have existed as far back as the Jurassic 

 epoch, ranges through the Cretaceous, and perhaps into the Tertiary. 

 Veniella proper, however, is, so fir as known, a Cretaceous group, and the 

 facf that it does not range into the Tertiary, and is unknown in the existing 

 seas, is another reason for regarding it as being distinct from Cyprina, which 

 occurs with it in the Cretaceous, and ranges to the present time. Dr. 

 Stoliczka criticises Mr. Conrad for speaking of Venilia, Morton, as a Creta- 

 ceous group only. In this, however, I think Mr. Conrad was right; for 

 whether we regard that group, as he and I understand it, as a genus or a 

 subgenus, it seems really to be confined to the Cretaceous. 



Fig n. 



Veniella « «> n i <> i> li o «• si , Meek. 



Plate 4, tig. 4. 



Shell rather thin, short, subquadrate or sub- 

 trapezoidal, with length only slightly greater than 

 the height, becoming extremely gibbous with 

 age, the convexity of large specimens sometimes 

 equaling the length; dorsal outline more or less 

 straightened, or, in large adult specimens, curving 

 downward somewhat posteriorly to the rather 

 short, truncated, posterior margin; basal margin 

 generally rather deeply rounded in outline ante- 

 Au anterior view, mainly to show riorly, and straightened or even slightly sinuous 



the couvexity of the shell. ■. ■,. , . . 



and ascendinn; posteriorly, to the posterior basal 



extremity, which is distinctly angular ; anterior side narrowly rounded below, 



and deeply sinuous under the beaks above; beaks prominent, very gibbous, 



Veniella goniophora. 



