U. S. NATIONAL MUSEUM 



BULLETIN 93 PL. 42 



^' 



la 



lb 



2c 



a 



2a 



2b 



2d 



V%^ 



rr 



y 



~:J 



X 



3 3a 3b 



1-2d, Balanus CRENATUS CURVISCUTUM; 3-3b, B. c. delicatus. 

 For explanation of figures see page 349. 



4 

 J 



