PLEUROTOMARIA. 



Shell spiral, turbinated, sometimes quite conical, and 

 having either a nearly square, or somewhat rounded aper- 

 ture, generally however of a rounded squarish form : the 

 outer lip being sharp edged ; and having near its upper 

 edge a deep notch or fissure near the suture. The extent 

 of this notch is proportionally much greater than in 

 Pleurotoma. There is no canal; and we feel it to be 

 important to repeat this circumstance, because some 

 who are but slightly acquainted with the Genus Pleurotoma 

 might else have enquired, wherein it differed from that 

 Genus, both having the notch in the side ; although inde- 

 pendently of this notch there is so much difference in 

 general form. 



