THE 
TRANSACTIONS 
ENTOMOLOGICAL SOCIETY 
LONDON 
FOR THE YEAR 1871. 
[= 
I. A Monograph on the Ephemeride. By the Rev. A. 
K. Eaton, B.A. 
{Read 5th December, 1870.} 
Part I. The Nomenclature of the Hphemeride. 
THE present communication is an introduction to a series 
of papers on the Hphemeride. In these papers I hope 
to give a detailed account of the organization and deve- 
lopment of some characteristic British species of the 
Family. My original plan was to treat of the British 
Fauna alone. In the course of my investigations, how- 
ever, I found that the nomenclature of the Family at 
large was corrupt, and therefore I have been led to review 
the synonymy of the whole group. In order to ac- 
complish this, I have been obliged to give at second- 
hand descriptions of many foreign species. These incor- 
porated descriptions I have, for the sake of uniformity, 
translated into Latin. 
Jt is always difficult, and sometimes impossible, to 
identify species by reference to mere colour descriptions 
and admeasurement, without recourse to the distinctions 
afforded by special structures. I have therefore avoided 
the use of analytic tables and diagnoses for the determi- 
nation of species. 
TRANS, ENT. soc. 1871.—partTi. (MARCH.) B 
