PLATE XXII. 



[Photo-microfjraphs by A. Scott. 

 Fig. 1. — Plankton showing (a) Biddulphia mohiliensis and (6) B. sinensis. 



X 25. 



Fig. 2. — Xauplius stage of Balanus. 

 X 30. 



Fig. 3. — Cvpris stage of Balanus. 

 X 30. 



