Mitglied des Teichplanktons." He also lists it ('98b)- from some 

 German streams. Marsson ( '00) found it in some waters near Berlin 

 in April- August, noting a great abundance in one instance in May. 

 Seligo ('00) gives a few statistical data indicating the occurrence 

 of Chydorus in the plankton of Hintersee near Danzig in April- 

 December, with a maximum in August and a secondary one in 

 October. It was, however, sparingly present in adjacent waters. 

 Cohn ('03) finds a like irregularity in its occurrence in waters near 

 Konigsberg. 



Stenroos ('97) finds it to be one of the most abundant Entomos- 

 traca in the waters of northern Russia and ( '98) a littoral and bottom 

 species near Helsingfors. Scourfield ('98) finds it to be one of the 

 most abundant Cladocera in the waters of Epping Forest, occurring 

 from March to December, with maxima of sexual reproduction in 

 April and November. Scott ('99) reports it as abundant in the 

 littoral fauna of Scottish waters, but rare in tow-net collections in 

 open water. 



It also occurs in the potamoplankton of European streams, 

 Zacharias ('98b) listing it from a few minor streams, but without 

 seasonal, statistical, or temperature data. It was not separately 

 listed by Skorikow ('97) in the summer plankton of the Udy at 

 Charkow, or by Lauterborn ('94) in the winter plankton of the 

 Rhine. Zimmer ( '99) found it from February to July in the Oder, 

 and Schorler ( '00) finds it abundant in the plankton of the Elbe in 

 April. Steuer ('01) finds it at all seasons in the backwaters of the 

 Danube at Vienna, and in the plankton from March to November 

 "oft in grossern Mengen," but gives no statistics of its seasonal 

 distribution. Fric and Vavra {'01) find it in the channel and 

 backwaters of the Elbe near Podiebrad, but more' abundant in the 

 littoral fauna, though no quantitative or statistical data of its 

 occurrence are given. Zykoff ('03) reports it as present in the 

 plankton of the Volga at all times in small numbers, and suggests 

 a predominance in May- July. Meissner ( '03) also reports it for the 

 Volga, but states that it is predominantly a member of the littoral 

 fauna though present in the plankton of the stream in restricted 

 numbers. No statistical data are given by him. Volk ('03) reports 

 it in the Elbe at Hamburg, but without any details. 



This species is reported generally from American waters. Forbes 

 C90) reports it in the summer plankton of Lakes Superior and 



