12 ARKIV FÖR ZOOLOGI. BAND 7. N:0 36. 



5. Eph. mi7iima (1. c. pag. 142. N.o 1644) is the same 

 species as the preceding one, but imago J" and probably, 

 like this, Coenis horaria (Lin.). 



6. Eyh. sulphurea(\. c. pag. 142. N:o 1645) is Fleptagenia 

 sulphurea auct., as accepted. 



7. Eph. gemmata (I. c. pag. 143. N:o 1646) is a mysterious 

 species, that cannot be determined with surety. 



8. Eph. diaphayia (1. c. pag. 143, n:o 1647). — Modern 

 authors bave, based on Eaton's^ authority, referred this 

 species to the genus Baetis and identified it with B. biocula- 

 tus auct., but, as I am convinced, wrongly. Muller himself 

 gives LiNNÉ's E. bioculata as identical. As I have tried to 

 show above pag. 5, this species cannot be identified with 

 Baetis bioculatus auct., but is undoubtedly the same as Cen- 

 troptilum luteolum auct., and according to my opinion, the 

 species in question must also be determined in that way. 

 The words in Muller's description, which seem to me ab- 

 solutely decisive, are »lepidota», »alae posticse nullse ; squamu- 

 Ise vero duae, subulatae», which characters, combined with the 

 other characters given, do not apply to any other species, 

 found in Danmark (or Norway) than Centroptilum luteolum 

 auct., imago J*. To some extent Muller's identifying of 

 the species with Linné's E. bioculata will also bear out my 

 above given determination. 



9. Eph. culiciformis (1. c. pag. 143. Nio 1648) is certainly 

 a Baetis. The description applies to imago J^, both of B. 

 tenax Eat. and B. scambus Eat. Most probably it is the 

 former. 



10. Eph. luteola (1. c. pag. 143. N:o 1649). — Eaton and 

 other modern systematici have referred this species to Cevtro- 

 ptilwn luteolum auct. To this determination apply Hagen's^ 

 words: »Your determination is possible, but that is all that 

 can be said about it». That Muller with this species has 

 intended the imago $ of either Baetis fuscatus (Lin.) or Cen- 

 troptilum luteolum auct., I think, in correspondence with 

 Eaton ^, but based upon partly other premises (ef. above 

 under N^o 8), indisputable, and it also seems to me most 



^ Träns, of Entom. Soc. 1871. p. 111 and Revis. Monogr. p. 158. 

 - H. A. Hagen, Notes on the Ephemerida? ; compiled (with remarks) 

 by the Rev. A. E. Eaton. Träns. Entom. Soc. London 1873. p. 400. 

 ■' 1. c. pag. 401. 



