EXPLANATION OF PLATES. 



PLATE I. 



Seasonal distribution of synthetic groups of planktonts, Chlorophycece, 

 Bacillariacea, and Mastigophora, from July 1, 1895, to October 171896. Note 

 changes of scale indicated at bottom of diagram. Numbers in column at left apply 

 only to 1895. In this plate and in II. and IV., apices exceeding the limit of the 

 diagram are dropped down between dotted lines to show location. Circles at 

 bottom indicate location of day of full moon. 



PLATE II. 



The same as above, from July 1, 1897, to April 1, 1899. Note change in 

 scale from previous plate. 



PLATE III. 



Seasonal distribution of total Rotifera and Crustacea from July 1, 1895, to 

 October 1, 1896. The Crustacea included, belong almost exclusively to the Ento- 

 mostraca. Apices exceeding the limits of the diagram are dropped down between 

 dotted lines to show location. Totals include both adult and immature stages of 

 the Entomostraca when detached from parent, and both free and attached eggs of 

 the Rotifera. 



PLATE IV. 

 The same as above, from July 1, 1897, to April 1, 1899. 



PLATE V. 



Seasonal distribution of Polyarthra platyptera. Total number of individuals, 

 not including eggs, represented by ordinants, parts of which exceeding 200,000 

 are represented by diagonal lines instead of solid vertical lines. Thus parts of a 

 seasonal plot which overlap those above it on the plate are represented by the 

 diagonally-lined ordinants. 



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