68 Rey. A. E. Eaton’s Monograph 
Genus Hpyemera. 
(Ala antica, in parte, Pl. I. fig. 9.) 
Bphemera, Lin. 1735.* 
Nympha fodiens. Segmentorum abdominis 1-7 bran- 
chiifera: laminarum prime minutissime, bipartite, di- 
midiis linearibus marginibus integris ; posteriores quoque 
duplices, sed dimidiis acute lanceolatis, marginibus bene 
fimbriatis. Palpimaxillares bi- articulati: superiores longi, 
hirsuti, secundo articulorum primo longiore: inferiores 
apicibus articulorum ultimorum dilatis, obliquis. Man- 
dibulze latus externum in cornu prorecto longissimo valde 
prorsus producitur. Frons breviter bicornuta, cornibus 
simplicibus. 
Alis conniventibus erectis, pedibus anticis elevatis et 
prorectis, sctisque caudalibus subparallelis, subimago 
quiescit. Setarum laterales inter se approximantur vel 
subtus vel supra mediam. 
Imago. Oculi integri; alee quatuor; sete tres longe, 
subeequales. ‘T'arsi postici quadri-articulati ; articulorum 
tres priores subeequales ; ungues dissimiles. Pedes for- 
cipis quadri-articulati, secundo articulorum longissimo. 
Ovivalvuld femina caret. 
Species of this genus usually appear in moderate 
numbers. The apical cross-veinlets of the marginal area 
of the fore-wing are variable in the same species. The 
pale spots of the thorax of the subimago, mentioned in 
the description of H. vulgata, are found in the other . 
EKuropean species. 
Ephemera vulgata. 
(Genitalia maris, Pl. IV. fig. 5, 5a. Maculee abdominales, 
fig. 5b.) 
Hphemera maculata, Lin. 1747. EH. vulgata [De G. 
1755]; Lin. 1758. H. communis, Retz. 1783. EH. danica, 
Ronalds, 1856. 
Subimago, v. v.s. Ale vel flavo-virentes, vel vires- 
centi-grisex, vel cinerez, nervis fuscis; anticee in medio 
fusco vel piceo maculate ; nervi transversales maris cor- 
vino marginati: margines terminales late griseo tincti. 
* Ephemerum, Hampe (1844), is a genus of the Phascei, an Order of 
the Acrocarpous Mosses. 
