PLATE 6 



EXPLANATION OP FIGURES 



Chaetopterus. Development in HCl and KNC 



21 A B Development in HCl m/2500 from thirty minutes after fertilization. 



22 Differential acclimation in HCl to/2500. 



23 A B Development in KNC m/100000 from twenty-four hour stage. 

 A lateral, B ventral view. 



54 



