PLATE VIII 



1 1 ! 



Series of the shells of ORTHIS ELEGANTULA, STREPTORHYNCHUS SUBPLANUM, RHYNCHOTRETA CUNEATA, 

 and REIV.IA EVAX, from the youngest form observed up to the adult or senile condition. The plate has been 

 drawn on stone from a photograph, and serves to show, not the details of structure, but the character and 

 completeness of the material which has served as the basis of this work. 



