NOMENCLATURE. 15 



scrol'icidali, Scrobiculate ; covered with small 

 pits or excavations. 



scripti. Lettered; marked with various charac- 

 ters resembling letters. 



s'mislri. Left-handed ; heterostrophous, turning 

 round the pillar from right to left, in- 

 stead of pursuing their usual, opposite, 

 course. 



spinoso-radiati, Spinosely radiate; beset with 

 spines in a circle, either concatenate, 

 united at their bases, or setaceous^ like 

 bristles. 



striati. Striate ; encompassed with very fine 

 raised or excavated lines : punctate strias 

 are those which have elevated or impressed 

 points placed along them; the points may 

 be concatenate^ strung like beads, or per- 

 tiise, deeply excavated. 



sulcati. Sulcated ; marked wath broader lines, 

 either hollow, ridged, or elevated. 



Apertura. Aperture, Mouth ; the orifice, en- 

 trance, or opening of the shell. 



llmarginaia. Bimarginate; having the lip with 

 a double margin. 



