INSTITUTE OF SCIENCE, PHILADELPHIA. 



87 



Cypraea (Siphocyprsea) problematica, nov. sp. Fig. 12. 



Shell ovately cylindrical, completely involute, exhibiting in the apical 

 region a deep comma-shaped depression prolongation of the aperture 

 which is wound dextrally around the axis of involution. 



Base plano-convex, slightly tumid superiorly ; aperture somewhat 

 eccentric, narrow, arcuate, continued into the comma-shaped depression 

 above referred to; canal short, broadly reflected; labrum with from 

 twenty to twenty-five prominent plaits, which are considerably stronger, 

 and much less crowded, than the equally numerous plaits on the colu- 

 mellar surface. 



Length, 2.7 inches; width, 1.4 inches. 



Common in the banks of the Caloosahatchie below Fort Thompson. 



This species is a much narrower shell than the Miocene Cypi'<za 

 Carolincnsis, and differs in like respect from all the larger Tertiary species 

 of the West India Islands with which I am acquainted. It most nearly 

 approaches in outline the recent Cyprcea cxantlicma, of the Florida coast. 

 The remarkable comma-shaped depression on the apical portion serves to 

 distinguish it readily from all other species of the genus, either recent or 

 fossil, that have come under my notice. 



Pyrula reticulata? Lam. 



Animaux s. Vertebres (Ficula), ix, p. 510. 



Tryon, Manual of Conchology, vii, p. 265, pi. 5, fig. 28; pi. 6, fig. 33. 



Caloosahatchie, in the banks below Fort Thompson. 



Mr. Tiyon separates the common species of the southern United 

 States (/'. papyratia of Say) from the eastern P. rcticulata, observing that 

 the shell of the former is slimmer and more delicately sculptured. 

 Whether these seemingly trivial characters are constant or not in the 

 living forms I am not prepared to say, but, obviously, the ornamentation 

 of the Florida fossil more nearly resembles that of Lamarck's species than 

 of the presumably distinct form described by Say. 



Natica canrena, L. 



Mus. Ulr., p. 674. 



Tryon, Manual of Conchology, viii, p. 20, pi. 4, fig. 58. 



Caloosahatchie, banks below Fort Thompson. 



Natica duplicata, Say. 



Journ. Acad. Nat. Sciences, Phila., ii, p. 247. 



Tryon, Manual of Conchology, viii, p. 33, pi. 12, fig. 3. 



Below Fort Thompson. 



Cruoibulum verruoosum, Reeve. 



Conch. Icon., ii, Crucibulum, Species 19. 

 Tryon, Manual of Conchology, viii, p. 119. 



