224 EXPLANATION OF TERMS. 



Muricated. Having little pointed knobs ; from 

 murex, the sharp point of a rock. 



Marine. Belonging to the sea ; from mare, the 

 sea. 



Multilocular. Having several chambers, from 

 mult us many, and locul um, a little 

 chamber. 



Operculum or Lid. A plate or door, with which 

 some species close the aperture of their 

 shells, from oper ior t I cover. 



Orbicular. Quite round, or circular. 



Parallel. Running in the same direction as 

 another thing, being always at the same 

 distance from it; from the Greek napa 

 (para) by the side of, and aXT^A wv (alle- 

 lon) each other. 



Pellucid. So clear that the light is seen through ; 

 from per, through, and lua?, light. 



Pervious. Easily passed through ; from per, 

 through, and via a way. 



Plicated. Folded or plaited ; from plica, a 

 fold. 



Punctured. Pricked or marked with small 

 dots ; from punct um, a point or dot. 



Patulous, lying open or spreading ; from pat er t 

 to lye open. 



Quincunx. Disposed alternately as in rows of 

 spots, when the spots of each row are 

 opposite to the space between two spots 

 of the next row ; from quin^we, five, and 

 unx, ounce, as the weight representing 

 five ounces was stamped thus :: 





