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University of California Publications in Zoology [Vol. 18 



Fig. 1. Ceratium gravidum. Original. Dorsal surface as seen from the dorsal 

 side. The outlines of the ventral area and other ventral structures seen through 

 from the dorsal side are shown in dotted lines. 



Fig. 2. The same, after Daday (1888, pi. 3, fig. 9). X 600. Showing the 



