///. 



MJ. 



112. 



1.2. 



I. 



2.1 



D 



Fig. 137, yl-Z>.— Reduction and destruction of zooids by a more advanced head region in 

 Stenostomum grande. A, portion of chain between XX and X'X' used; B-D, stages of destruc- 

 tion; cellular material from destroyed parts in pseudocoel indicated by dots (from Child, 

 19036). 



