201 
GLOSSARY 
OF 
TERMS USED IN CONCHOLOGY. 
Acuminated, terminated in a sharp point. 
Anterior, (in Univalves) the part which forms the spire : — 
(in Bivalves), see Margin. 
Aperture, the orifice or opening of the shell; it is called an- 
gular, when its circumference has several angles: bz- 
marginated, when the right lip forms a double margin: 
coarctate, contracted: compressed, flattened: gaping, when 
one of the extremities is wider than the other: linear, when 
narrow, and the length greatly exceeds the breadth: trans- 
verse, when the breadth is greater than the length. 
Apex, the tip or small end of a shell. 
Articulated, (applied to Multivalves), when the different pieces 
of which the shell is composed are so strongly united, that 
they appear to form one shell: (when applied to Bivalves), 
see Teeth. 
Auriculated, having ears. 
Base, (applied to Multivalves), the part on which the shell is 
supported: (to Univalves), the most elevated part of the 
shell opposite to the spire. 
