4 ARKIV FÖR ZOOLOGI. BAND 7. N:0 86. 



PiCTET^ who identified Linné's and Fabricius' species 7nar- 

 ginata, explained it as Potmnantlms marginatus, wbich, how- 

 ever, as is clearly shown especially by the lengthened, narrow 

 fore-wings »avec les nervures peu abondantes», the hind wings, 

 relatively small, with »moins compléte nervation» and by the 

 illustrations, is a very separate form. 



3. Eph. vespertma (Fauna Suec. p. 378. N:o 9. — System. 

 Nat. Ed. XII. p. 906. N:o 4). — This has been a very my- 

 sterious and disputed species among låter systematici. At 

 first Eaton ^ considered it as representing a typical Lepto- 

 phlebia, but referred it låter ^ hesitatingly to the genus Blas- 

 turus and puts it, according to his latest interpretation'^, 

 with a note of interrogation as s3monymous with his Lepto- 

 phlehia Meijeri. As a Cloeon it was determined, according 

 to Eaton (1884), by Oulianine^. Wallengren ^ thinks, that 

 it »sannolikt» is subimago of Hahrophlehia fusca (Curt.). It 

 seems to me that the characters mentioned by Linné — 

 which characters must be supposed to be founded on dried 

 material of subimago — »toto corpore et alis superioribus 

 nigra, solae alse inferiores albse», combined with the size men- 

 tioned (»est inter minores generis sui») and »cauda triseta» 

 are not applicable to any other Swedish species known than 

 to Euphyurus alhitarsis Bgtn. Cf. S. Bengtsson, Beiträge 

 zur Kenntn. d. paläarkt. Ephemeriden. Lunds Univ. Årsskr. 

 N. F. Afd. 2. Bd. 5. 1909. p. 5. LeptopJilebia 31 eyeri Eat., 

 of which I have låter had an opportunity of examining au- 

 thentic specimens, is synonymous with this one. The species 

 should thus take the name of Eup)liyvrus vespertinus (Lin.). 



4. Eph. bioculata (Fauna Suec. p. 376. N:o 1473. — 

 Syst. Nat. p. 906 — 7. N:o 5). — Almost all authors have inter- 

 preted this species as Bactis biocidatus auct. but, as I think, 

 wrongly. The characters »alis albis reticulatis», »tubercula 

 . . . lutea . . . pellucida», »abdomen . . . albo diaphanum», 



^ F. J. PiCTET, Hist. natur. d. Ins- Névropt. Famille des Ephémérines. 

 Geneve 1843. p. 208. Pl. XXV. Fig. 4 and 5. 



^ A. E. Eatozst, a Monogr. on the Ephemeridse. Träns. Entom. Soc. 

 London 1871. p. 88. 



^ A Revisional Monograph of recent Ephemeridae or Mayflies. Träns. 

 Linn. Soc, London 1884. p. 103. 



* Entom. Montbl. Magaz. Vol. 37. London 1901. p. 253. 



^ Neuropt. and Orthopt. of the province of Moscou. 1867 (cited ac- 

 cording to Eaton.) 



^ H. D. J. Wallengren, Förteckning etc. p. 176. 



