NOMENCLATURE. 29 



species of the Genus Anomia adhere to 

 foreign substances. 



Labia. Lips. 



interna. - Internal ; the small lips within the liga- 

 ment, which are united by it. 



hiantia. Gaping : when the lips are wide, or dis- 

 tant from each other. 



retracta. Retracted ; opposed to prominent. 



truncata. Truncate; shorter than the suture. 



externa. External ; the margins of the area, or 

 anterior slope about the ligament. 



incumbentia. Incumbent ; when one of the ex- 

 ternal lips hangs over the other. 



Ligamentum. Ligament; a cartilage which 

 closes the suture, and is affixed between 

 the internal and external lips of the shell, 

 connecting the valves. 



Limbus. Limbus; circumference within the 

 margin. 



Longitudo. Length, measuring from the 

 summit to the opposite margin ; and the 

 breadth, Latitudo, in a direction at right 

 angles to this. 



