INSTITUTE OF SCIENCE, PHILADELPHIA. 37 



part is just behind the next suture, which it seems to overhang. It has not 

 the fine, even interstitial spiral striation oi D. lissotropis, but has sparse (on the 

 upper whorls two or three) incised lines, more numerous on the base, where 

 the interstices are slightly elevated and rounded. On the first three or four 

 whorls, after the nucleus, the ribs are largest and subnodulous at the anterior 

 border of the whorl, giving the tip a coronated look. It is almost exactly the 

 size of Z>. lissotropis. Two immature specimens were obtained in the Caloosa- 

 hatchie beds. 



Drillia Simpsoni Dall. 



Pleurotoma Simpsoni Dall, Proc. Dav. Acad. Sci. v. p. 54, 18S7. 

 Drillia Simpsoni Dall, Rep. Blake Gastr., p. 91, 18S9. 



Caloosahatchie beds. Recent, North Carolina to Florida in moderate 

 depths of water. 



Drillia ebur Reeve. 



Pleurotoma ebur Reeve, P. Z. S. 1845, P- n^ ; Conch. Icon., Pleurotoma, pi. xxx. fig. 275, 



Dec. 1845. 

 Clavus ebur Tryon, Man. vi. p. 188, pi. xiii. fig. 56, 1884. 

 Drillia ebur Dall, Rep. Blake. Gastr., p. 89, 18S9. 



Fossil, Caloosahatchie beds. Recent, in moderate depths, from North 

 Carolina to Florida and in the northern Antilles. 



Genus MANGILIA (Leach) Risso. 

 Many of the species cited being known only from their shells, the reference 

 of them to one genus or another must be regarded as provisional. They have 

 been assorted by the general habit of the shell, which is the only guide we 

 have, and which is not without value when its recognition is deduced from 

 sufficient study of recent forms. The present genus includes all PleurotoniidcB 

 without opercula, following the arrangement of the distinguished French 

 paleontologist. Dr. Paul Fischer. The subordinate divisions recognized for 

 the purposes of this paper are ; 



Subgenus Oythara Schumacher. 

 Subgenus Daphnella Hinds. 

 Subgenus Glyphostoma Gabb. 

 Subgenus Mangilia Risso ; s. s. 

 Subgenus Pleurotomella Verrill. 



I have enlarged on the characteristic features of these groups in my 

 Report on the MoUusca of the Blake Expedition, recently published, to which 

 readers are referred for more detailed information. 



Subgenus Oythara Schumacher. 

 Cythara balteata Reeve. 

 Mangilia balteata Reeve, Conch. Icon., Mangilia, fig. 57, 1846. 



Caloosahatchie beds. Recent from North Carolina to the West Indies 

 at moderate depths. 



