

MURICIDJE. 131 



Trichotropis (Broderip). Shell thin, spirally 

 furrowed, umbilicated ; pillar obliquely truncated. 



T. acuminata. 



borealis. Fig. 208 ; n. s. 



Murex (Linn.). Bock-shell. Shell roughened 

 with periodical expansions of its lip (varices) , which 

 are permanent after the lip has advanced ; canal 

 partly closed. 



M. erinaceus. Fig. 209; n. 

 corallirms. 



K 2 



