Xii GLOSSARY. 



Plaitedf when the columella is toothed, as in Volutes. 

 Posterior, see Margin. 



Reticulated, like net- work. 



Retuse, when the lower whirls are pressed into the body. 



Rostrum, see Beak. 



Rugose, wrinkled. 



Scabrous, rough. 



Serrated, toothed like a saw. 



Semilunar, like a half-moon. 



Sessile, low, dwarf. 



Sinuous, waved. 



Sinus, a deep cut, as in the lip of the Murex Babylonius. 



Slope, the side from the beaks. 



Spinous, having prickles or thorns. 



Spire is formed by the whole of the upper whirls. 



Striae, lines, flat or slightly raised: they are called longi- 

 tudinal, when they run from hinge to margin : trans- 

 verse, wihen in a contrary direction: and concentric, 

 when they fonn segments of circles. 



Suhcordate, approaching the form of a heart. 



Subpellucid, not quite clear. 



Subulate, tapering. 



Superior, see Margin. 



Suture, a toothed joint. 



Syphon, a prolonged tube running through the partitions 

 of chambered shells. 



Teeth, (in Univalves), angular plaits, as on the pillar lip 

 of Volutes: (in Bivalves), pointed protuberances with- 

 in the hinge, by which the valves are united. They 

 are called: alternate, when the teeth of one valve are 



