Tor NorTHERN MucROscoPIst. 



Waits. MARCH. 1882. 


A NYMPH OF THE GENUS CANIS. 
(FAMILY EPHEMERIDZ,*) 
By W. B.Lackspurn, F.R.M.S. 
HE name “ Ceenis ” was derived from the mythology of ancient 
Greece, and applied to this genus of insects, Czenis was a 
woman beloved by Poseidon, and changed by him into an invulner- 
able man, who engaged in the wars between the Lapithz and 
Centaurs. As they were unable to kill him, the Centaurs buried 
him alive, when he became changed into a bird, and afterwards 
into a woman again, whom Aéneas is described by Virgil as meet- 
ing in Hades, in the “ fields of mourning ” set apart for the solitary 
wanderings of the shades of unhappy lovers. (A®neid vi., 448). 
The supposed resemblance between the entomological Czenis and 
its mythological prototype I leave to be explained by those who 
delight in efforts of the imagination. 
Other generic names have been given by various authors to 
specimens of this genus, amongst which I may mention Lphemera 
by Linné and Fabricius, Brachycercus by Curtis, Oxycypha by 
Burmeister, Macrocercus by Westwood, and Cloé or Cloéon by 
others. The Entomological Society have, however, given their 
approval of the name Cenis, by which the genus is at present 
known. 
The imago is easily recognized, as it is the only two-winged 
British genus that has three caudal setze or tails ; the other two- 
winged genus, Cloéon, having only two tails. It may also be 
known by the comparative shortness and great breadth of its wing, 
the longitudinal nervures of which are simple, with few transverse 
nervures, and, in the typical species at least, without interneural 
veinlets arising from the terminal margin, which is ciliated in this 
genus ; by the abdomen being little longer than the thorax and 
scarcely extending beyond the posterior margin of the wing ; and 
by the size and width of the thorax and head, which proportionately 
exceed those of Cloéon. The compound eyes of the male consist 
of a single pair, the large pillared eyes of the male Cloéon being 
absent. ‘The tarsi have five joints, the fifth joint being sometimes 

*A paper read before the Manchester Microscopical Society on 2nd Feb. 
VoL. 2. 

