1885.] 



CLADOCERA. 



43 



the end of September, when I foimd it rather abundant iu 

 two of the aquaries. Xay. in one — a comparatively small 

 cyliudric glass — it swarmed about in such profusion through 

 the mud, that I could always make sure of securing several 

 specimeus by taking up with a small dipping-tube a very trilling 

 quantity only of the mud. In some of the specimens, winter- 

 eggs had been deposited in the matrix — easily distinguished 

 from summer-eggs by their dark-yellowish colour. Only 2 such 

 eggs occurred in each individual, and no perceptible modifica- 

 tion of the dorsal part of the carapace was ever observed in such 

 cases. Of males, only a few specimens were found at that time. 



