PLATE 6 



EXPLANATION OF FIGURES 



21 and 23 Gill-plate prophases of class II. Chromosomes '/,' figure 21, inter 

 preted as one; 'i,' figure 23, as two (p. 12). 



22 A peritoneal complex with part of the chromosomes missing. 



24 A peritoneal complex separated into two parts. The i)air numbers ar 

 duplicated in figure 31 and, in the legend of figure 37. 



238 



