on the Ephemeride. 105 
Long. al. 9, corp. 6 mm. 
Hab.—France ; probably near Paris. 
The name will not obtain, Curtis having previously 
applied “ C. obscurum” to C. dipterum, subim. 
Oloeon russulum. 
(Forceps, Pl..V. fig. 12.) 
Ephemera russula, Mul. 1776. Cloeon dimidiatum, 
Curt. 1834. H.culiciformis & striata (?), Blanch. 1840. 
Cloe pumila, Ramb. 1842. Cloe dimidiata, Pict. 1843-5; 
Cloeon dimidiata & Coeenis sinensis, Walk. 1853; Chloeon 
dimidiatum, Lubbock, 1863 & -5. Cloeopsis diptera, var., 
Htn. 1866 & -7. 
Subimago, v. v.s. Ales cane; apud crassiores ner- 
vorum spe gramineo tinctz. Sete cinerascentes. 
Imago, v. v. s. Variabilissima colore: ¢ maribus 
Cloeonis similis, Baetis binoculati atque varietatum hujus, 
? uxoribus Centroptili luteoli et Baetis binoculati colore 
similis. 
Var. 1. ¢. Cloeoni simili similis. Oculi turbinati 
fuhiginosi. Tergum thoracis aterrimum politum. Pedes 
pallide virescenti-flavescentes, tarsis nigricantibus. Ab- 
domen saturate fuscum, juncturis flavescentibus, tracheis- 
que subcutaneis atris. Sete albs, juncturis rufescenti- 
bus. Forceps albus, apices versus nigricans. 
Hab.—Reading (Berkshire), and near Cambridge; as 
well as in the Valais Canton, near Visp. 
Var. 2. &. Baeti binoculato similis. Oculi turbinati 
sulphurei vel flavi; inferiores fuliginosi, vel virescenti- 
cinerel, vel etiam glauci. Tergum thoracis fuscum, vel 
fusco-luteum, vel saturate furfurosum vel testaceo-furfu- 
rosum. Alze vitrine ; nervule apicales areee marginalis 
(6-8) oblique, interdum sparse furcatze prope subcostam. 
Pedum antici virescenti-grisei, tibiis tarsisque griseis vel 
canis; posteriores cretacei vel sulphurei, tibiis tarsisque 
obscure albis. Segmentorum abdominis 3-6 vel 7 alba, 
vix aut ne vix quidem lurido suffusa; cetera supra fur- 
furosa vel fusca, juncturis ochraceis, et subtus plus aut 
minus ochracea. Sete albz, juncturis interdum anguste 
obscuris. 
