GLOSSARY. Xlll 



received between the teeth of the other valve: articu- 

 lated, when the tooth is received into a corresponding 

 cavity in the opposite valve : cardinal, the central tooth 

 or teeth of the hinge : compressed, when flattened : erect, 

 perpendicular to the plane of the hinge : forked, hav- 

 ing the point divided into two: longitudinal, when it 

 extends along the margin. 



Tubercle, a protuberance or knob. 



Tuberculated, having elevations resembling warts. 



Tubular, (applied to Multivalves), when the greater part 

 of the shell is cylindrical. 



Turbinated, when the belly of the shell is large in propor- 

 tion to the spire, which seems to proceed from the centre. 



Valves, the different pieces which compose the shell. 



Varix, Varices, longitudinal elevations or ribs, formed by 

 the junction of the different additions the shell has re- 

 ceived. 



Vcntricose, swollen. 



Vermiform, having the form of worms. 



Vertex, the top or point of a shell. 



Umbilicated, having a hole in the base of the pillar. 

 Umbo, the summit. 

 Undulated, waved. 



Whirl, a spiral convolution. 



