AuTU'LE V. — Li fit of the Described Species of Fresh Wnter 

 Crustacea from America., North of Mexico. By Lucien 

 M. Underwood, Ph.D. 



INTRODUCTORY. 



The econoniic relations of the fresh water Crustacea are 

 rapidly calling them into general notice, since their importance 

 oo fVio nafnvnl fnnri snniilv nf manv of onr most valnahltt fishps 



ERRATA. 



On page 333 after Tachidins read Lilljeb. 



On page 338, under DaphneUa hrachyura insert Hah. 

 Massachusetts (Birr/e), Minnesota (Herrick). 



On page 340, for Scapaoleheris read Scapholeheris. 



Brady, etc., it has not been thought desirable to repeat this 

 synonymy, but merely to refer to the author giving it in full. 

 For this reason all the European pai3ers are not repeated for 

 all the species they describe. In the American literature, how- 

 ever, it has seemed desirable to give every reference to each 

 species, even at the risk of too great repetition. 



The study of our fresh water Crustacea, with that of their 

 marine congeners, commenced with Thomas Say, and has since 

 attracted the attention of over thirty different writers, nearly 

 all of whom have added one or more new species to our lists. 

 Certain groups, like the PlnjUopoda and Asfacida', have been 

 carefully monographed, and furnish a literature of great value; 

 in others sufficient work has been accomplished to furnish a 

 broad, if not a substantial, basis for further study; while in 



