4 GLOSSARY. 



lateral, when placed on one side of the shell: reflected, 

 when its edges are folded over the exterior margin : ter- 

 minal, if situated at the extremity of the shell: and 

 truncated, if the beaks of the shell appear to have been 

 transversely cut off, and the teeth of the hinge fixed to 

 this part. 

 Hispid, covered with hairs, as in the lielix hispida. 



Imbricate, when the surface is covered with scales parti- 

 ally over-lapping each other. 



Imperforate, having no umbilicus. 



Inequilateral, when the anterior and posterior parts of the 

 shell are dissimilar. 



Inequivalve, when the valves are dissimilar. 



Involute, without a spire, as in the Patellje. 



Keeled, see Carinated. 



Labium, see Lip. 



Le7iticular, when the valves are round, and diminish in 



thickness from the centre towards the edges. 

 Lid, see Opercidum. 

 Ligament, a membranous substance which connects the 



valves: it is both interior and exterior in the generality 



of Bivalves. 

 Linear, when the length of the shell is greater than its 



breadth, and its form not cylindrical. 

 Linguiform, tongue-shaped. 

 Lip, (in Univalves), the sides of the aperture : (in Bivalves), 



the exterior edge of the valves. 

 Lunar or Lunate, having a crescent form. 



Margin, the edge of the shell: anterior, the space in which 

 the ligament is situated; posterior, the space on the 



