NOMENCLATURE. 89 



Spiralis, Spiral ; so twisted that an imaginary 

 plane passing through the middle of the 

 outer whorl shall bisect all the others, or 

 divide them into two equal parts. 



iurrita, Turreted ; the whorls gradually atte- 

 nuating or decreasing in the form of a 

 cone : the length of these shells always con- 

 siderably exceeds their width. 



turlinata. Turbinate ; the belly vswelling or tu- 

 mid ; the spire comparatively small, rising 

 as it were from the hollow of the body. 



umhiiicata. Umbilicate; possessing an umbili- 

 cus. 



Varices, Varices; longitudinal gibbous su- 

 tures formed in the growth of the shell 

 at certain proportionable distances on the 

 whorls. 



continuati. Continuous ; running through all the 

 whorls. 



decussati. Decussate ; longitudinally and trans- 

 versely divided or crossed. 



scroUcidatu Furrowed; engraven with cavities 

 towards the margins. 



