RECENT FRESHWATER INVESTIGATIONS 315 



vided and the forms in each. Here also Lemmerinann (95, 

 96a). Lemmermnan (96), Miiller (98) and Schroder (98) report 

 on the flora of the lakes in the Rlesengebirge, and the latter 

 undertakes to distinguish the formations of the freshwater 

 algae, as limnophilous, potamophilous, sphagnophilous creno- 

 philous, geophilous, lithophilous and kryophilous, giving 

 faunal data regarding each. Concerning other local floras 

 there is noted the report of Pieters (9-i) on that of Lake St. 

 Clair, Thompson (96) on Lake Michigan and Whipple, Jelliffe 

 and others on the flora of city water supplies in this country. 



On the flora of ponds used for fish culture Lemmermann (97) 

 and Schroder (97) have made some investigations. The 

 former reaches certain preliminary conclusions as to the eco- 

 nomic worth in such ponds of different forms of vegetation. 



The freshwater fauna may be considered from two main 

 standpoints which indicate thus principal subdivisions of the 

 subject. One may investigate the forms of which it is consti- 

 tuted or the location in which these forms are found, discussing 

 accordingly first their composition and second their distribution. 



Regarding the composition of the freshwater fauna it may 

 be said that nearly every paper listed in the bibliography con- 

 tributes some notes of importance. Under this heading, how- 

 ever, it is the intention to bring together briefly only those 

 which for one reason or another lay particular emphasis on 

 this feature, dealing with taxonomic groups of various size in 

 their faunal relations. As noted previously the bibliography 

 makes no claim to completeness on extra-plankton topics. Its 

 shortcomings are undoubtedly most noticeable under the present 

 heading. Greater attention has naturally been devoted to con- 

 tributions treating of North American forms while literature on 

 freshwater vertebrates has been entirely omitted, and that on 

 insects almost wholly. 



On Protozoa Blochmann presents a very satisfactory general 

 summary. Schewiakoff (93a) is the most important contribution 

 on the group within the limits of this review. In Europe Le- 

 vander (94a), Entz (96), France (97), deal with the protozoan 



