22 NOMENCLATURE. 



fusiformis. Fusiform ; intermediate between co- 

 nical and ovate, or tapering and a little 

 ventricose. 



imbricata. Imbricate ; with plaits parallel to the 

 margin. 



interrapta. Interrupted ; continued by new ac- 

 cretions, or additions of the shell. 



involuta. Involute; having the margin of the 

 exterior lip turned inward. 



lineis crispata. Wrinkled ; rendered rough by 

 flexuous lines. 



marginata. Marginate ; the sides of the shell 

 being thickened. 



obovata. Obovate ; nearly oval, but narrower and 

 produced at the base instead of the apex. 



perfoliala. Perfoliate ; having a horizontal suture 

 girt with a deflex or overhanging margin, 

 as if one shell were placed upon another. 



polythalamia. Chambered ; divided internally by 

 various partitions. 



radkaia. Radicate ; affixed by the base to some 

 foreign substance. 



rostrata. Rostrated ; beaked. 



