18 NEW YORK STATE MUSEUM 



known, having been described by Walsh, its discoverer, and by 

 Vayssiere and Eaton. In bulletin 47 I described the nymphs 

 (having in each case bred the species) of Heptagenia 

 pule hell a Walsh, Baetis pygmaea Hagen, Siphlu- 

 rus alter natus Say, Ephemerella excrucians 

 Walsh, Caenis diminuta Walker, Hexagenia varia- 

 bilis Eaton, and Ephemera varia Eaton. In the Ameri- 

 can Naturalist for 1903, pp.25-31 of vol.37, Mr Edward W. Berry 

 described the nymphs of ?Habrophlebia americana 

 Banks, Blasturus cupidus Say and Gallibaetis fer- 

 r u g i n e a Walsh, and in Bulletin 68 I described the nymph of 

 Gallibaetis skokiana Needham. That is all the bred 

 species that have hitherto been described in Aimerica, so far as I 

 know. 



In the following pages I describe the nymphs of the following 

 eight bred species, representing as many genera : Chiroten- 

 e t e s a 1 b o m a n i c a t u s sp. nov. Ohoroterpes basa- 

 1 i s Banks, Leptophlebia praepedita Eaton, Caenis 

 alloc t a sp. nov., Ameletus ludenssp. nov. Ephem- 

 erella bi sp i na sp. nov.. Hep t ageni a inter punctata 

 Say, and Ecdyurus maculipennis Walsh, Mr W. E. 

 Howard furnishing an account of the life history of P o 1 y m i - 

 tarcys albus Say, which he has studied at Ottawa 111., but 

 which I have not seen at large. I add thereto descriptions of 

 five additional species which have not been bred, but to which the 

 names of native genera are assigned tentatively. 



Some of the above descriptions are generic rather than specific : 

 the study of the nymphs in some genera has hardly gotten down 

 to the species as yet. Kepresentatives of all these genera are de- 

 scribed and figured in Eaton's Monograph of Recent EpTiemeridae, 

 at least two of them being tentatively referred to the wrong gen- 

 era, however. But the excellent and copious figures of that 

 work make it possible to refer the five species of unbred nymphs 

 to their genera with some degree of assurance. 



I have published directions for collecting and rearing nymphs 

 of mayflies elsewhere,^ but while speaking of life histories I would 

 not omit to mention how easy it is to get life-history material in 



iPart of Bull. 39, U. S. National Museum. 



