52 University of MicJiigan 



PLATE II 



The scales indicate a length of one millimeter. 



Fig. /. LucidcUa vcnczucloisis. Front view of shell and outer view 

 of operculum (calcareous plate). 



Fig. 8. Tiidora wilUaiiisoni. Outer view of operculum and front 

 view of last whorl of type specimen (male). 



Fig. 9. Tudora pUcatida. Outer view of operculum. 



Fig. 10. Tudora mcgachcUos. Outer view of operculum. 



