INSTITUTE OF SCIENCE, PHILADELPHIA. 83 



of the crown, and a more pronounced straight-sidedness in the bounding 

 lines of the shell. The number of such specimens in our collection is 

 not very great, and scarcely sufficient to warrant a specific separation of 

 the form from the species just described. 



Named after Geo. W. Tryon, Jr., the distinguished conchologist of 

 the Academy of Natural Sciences of Philadelphia, from whom the 

 author has received much valuable assistance in the preparation of this 

 and other paleontological papers. 



Conus Hercati ? Brocchi. 



Conchiologia Fossile Subapennina, ii, p. 287, pi. 2, fig. 6. 



Homes, Die foss. Mollusken d. Ttrtiarbeckens von Wien, ii, p. 23. 



Shell obconical, broad, straight-sided ; spire moderately elevated, 

 gradually sloping for about six volutions, then abruptly elevated in the 

 apex; total number of volutions about twelve; surface smooth ; aperture 

 nearly straight and parallel-sided ; columellar folds obscure. 



Length, 2.3 inches; width, 1.3 inches. 



Caloosahatchie, banks below Fort Thompson. 



The species of cone here described so closely resembles in its 

 general features Conns Mcrcati of Brocchi that I fail to find any distin- 

 guishing characters by which to separate it from that form, with which I 

 have accordingly doubtfully united it. It must be admitted, however, 

 that the determination of the species of Conus is a very difficult one, 

 rendered doubly so in the absence of all color-markings. In our speci- 

 mens, unfortunately, no markings remain ; hence, despite the general 

 agreement, some little uncertainty must still attach to an identification 

 which neglects one of the primary distinguishing characters. 



The species is apparently also closely related to a Santo Domingo 

 fossil which Gabb identifies (doubtfully) with Michelotti's C. Bcrghausii, 

 but differs from it in the more pronounced angulation of the shoulder, 

 and the greater elevation of the apex. From the Miocene Conus Mary- 

 landiciis, of Conrad, it can readily be distinguished by its much greater 

 width, the comparatively depressed spire, and the absence of carinations 

 on the whorls of the spire. 



Conus cateuatus ? Sowerby. 



Quart. Jour. Geol. Soc. London, vi, p. 45, pi. ii, fig. 2. 



I refer to this species a number of small cones which agree so 

 closely with the Santo Domingo fossil as to be barely separable from it. 

 The only differences that I can detect, and these are but very faintly 

 indicated, are a slight concavity in the outline of 6". catenates, and a 

 somewhat more pronounced elevation above one another of the whorls 

 of the spire. 



