234 



PYRAMIDELLIDyE. 



Genus aclis, Loven. 



Operculigerous lobe ample, developed more on the 

 right side, where it is three or four plicated, than on the 

 left, where it forms a single, rounded lobe. 



Shell turreted, many-whorled, whorls smooth or spirally 

 striated ; aperture oval or rounded ; inner lip simple, 

 without plaits or teeth, base often perforated. 



Si/ii. Ebala, Gray. 



Ex. A. nitidissima, Montagu, pi. 24, fig. 9. Shell, 

 A. nitidissima, fig. 9, a. 



In Aclis the foot is linguiform, much produced ante- 

 riorly, and the cylindrical tentacles are slightly swollen at 

 their tips ; its other characters are similar to those of 

 the other genera in the family. The species are few in 

 number and small, though exceedingly elegant. 



Species of Aclis. 



acuminata, Sow. (Scalaria). 

 ascaris, Mont. 

 nitidissima, Mont. 



supranitida, S. Wood. 

 unica, Mont. 



Genus monoptygma, J. Lea. 



Shell elongated, imperforate, many-whorled, transversely 

 striated ; aperture small, entire in front ; columellar lip 

 with a single, obscure, winding plait j outer lip simple, 

 acute. 



Syri. Monotygma, Gray. 



