FAUNA OF OETHAULAX PUGNAX ZONE. 55 



shell. The specimen figured is from the Miocene of South Carolina, 

 the White Beach specimen being too poor to figure. 



MARGINELLA GREGARIA, new species. 



This species, in my original studies from imperfect material sup- 

 posed to be a variety of M. Umatula^ seems now, from material 

 received too late for figuring, to be quite distinct. I therefore 

 describe it comparatively until an opportunity may arise when I can 

 supply a figure. 



The shell is of a shape not unlike M. limatula^ but longer and more 

 ovoid. Its relative diameter at the shoulder of the last whorl is much 

 less and the outer lip at the shoulder is therefore less prominent. 

 The thickening of the outer lip is less pronounced, and in all the 

 specimens received it is perfectly smooth, while in 71/. limatula fully 

 adult specimens have it finely denticulate on the inner edge. The 

 plaits are also much more delicate than in M. limatula. Comparative 

 measurements are as follows: 



M. gregaria: Length 17.5, maximum diameter 9.3, length of aper- 

 ture 15 mm. 



M. limatula: Length 14.7, maximum diameter 9, length of aperture 

 13 mm. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida ; Dall and 

 Post. U. S. Nat. Mus. No. 165081. 



M. gregaria somewhat resembles M. onchidella Dall, of the Plio- 

 cene, but is smaller and less arcuate laterally, with the spire more 

 apparent. The specimen of BI. limatula measured above is that 

 figured on plate 11, figure 7, of this paper. 



MARGINELLA BELLA Conrad. 



Plate 16. flg. 10. 



Prunum Jjrlla (sic) Conrad, Amer. Jouni. Conch., vol. 4, p. 67, pi. 6, fig. 4, 

 1868; Proc. Acad. Nat. Sci., Phila., for 1862, p. 564 (name only). 



Marginella iella Dall, Trans. Wagner Inst., vol. 3, pt. 1, p. 53, pi. 4, figs. 9«, 

 1890. 



Oligocene of the Tampa silex beds and of the overlying Orbitolite 

 bed at Ballast Point, Tampa Bay, Florida ; Burns and Dall ; Miocene 

 of Virginia ; Pliocene of the Caloosahatchie Eiver, Florida ; living off 

 the coast of North Carolina on sandy bottom in 14 to 50 fathoms. 

 U. S. Nat. Mus. No. 165052. 



This species was the type of Conrad's undefined group Porcella- 

 nella, which he afterwards abandoned. Among Conrad's original 

 specimens two species were represented, one of which he had already 

 named M. succinea, the other will retain the present name. Figure 9" 

 of the Wagner Transactions represents the normal form. The recent 



