140 THE ELEMENTS 



Alated, winged, applied to the ex- 

 panded lip of the Strombus genus. 



Ambitus, the circumference or out- 

 line of the valves. 



Annulate, formed or divided into dis- 

 tinct rings, or marked with differ- 

 ently-coloured annulations. 



Antiquated, longitudinally furrowed, 

 but interrupted by transverse fur- 

 rows, as if the shell had acquired 

 new growth at each furrow. 



Anus, a depression on the posterior 

 side near the hinge of bivalves. 



Aperture, the mouth or opening of 

 the shell. 



Apex, the tip or point of the spire. 



Apophysis, an excrescence. 



Approximating, approaching near to, 

 or near together. 



Arcuated, bent in the form of an arch, 

 incurvated. 



Arcuations, bendings, curvings. 



Area, the surface contained between 

 lines or boundaries. 



