BIOLOGICAL BULLETIN, VOL. XXXvlll 



PLATE III. 



A A 



CC BB 



23 



* ^3 

 



24 



|ff \ 4*^ * A 



2 7 



s -~. 







31 



er--- 



TlV 



c r: 



29 



\ 



v 



i 



--_ 





ELMER L. SHAFFER. 



