U. S. NATIONAL MUSEUM 



BULLETIN 93 PL. 24 





1b 





3a 



3b 







5d 



1-2, BALANUS EBURNEUS; 3-3B, 5-5o, B. IMPROVISUS; 4, B. AMPHITRITE PERUVIANUS. 



FOR EXPLANATION OF FIGURES SEE PAGE 343. 



