on the Bphemeride. 5d 
The curious species comprised in this genus appear in 
considerable numbers towards evening. The males of 
the extra-European species being at present unknown, 
I have not separated the group, in spite of the differ- 
ences of their wings. My divisions of the genus may be 
tabulated as follows :— 
Ale anticee radius et subcosta confluentes : nervorum 
longitudinalium sequentium primus— 
et tertius bifidi; secundus obsolescens bipartitus :— 
O. Trimeniana : 
bipartitus; secundus simplex ; tertius— 
bifidus :—O. rhenana et pallida, (Pl. I. fig. 2). 
simplex :—O. anomala. 
Oligoneuria anomala. 
O. anomala, Pict. 1843-5. 
Imago ?,s.s. ‘‘ Corpus fuscum vel brunneum. Ale 
pallide grisez ; antice: nervis transversalibus circa sex. 
Setze longe pubescentes, pube sparsi bases versus.” 
(Hag.) 
Long. corp. ? 13, set. 8, exp. al. 32 mm. 
Hab.—Rio Janeiro (Koll. MS.). 
Oligoneuria rhenana. 
(Genitalia maris, Pl. III. fig. 7; caput, fig. 7a.) 
O. rhenana, Imh. 1852. O. anomala, pars, Pict. 1843-5. 
Subimago, v. v.s. Ale fumatie, costas versus satura- 
‘ tiores. Setarum bases glabrae, apices pilosi. 
) Imago, v. v. s. Oculi atri; caput et thorax lutes- 
\\ centes. «© Abdomen albicans, segmentorum apices versus 
ochraceo tinctum,” juncturis obscuris, et setis albis. 
Pedum antici fuliginosi ; posteriores albi, femoribus cre- 
taceis et unguibus obscuris. Alarum crassiores nervorum 
saturate fumati. 
@. Corpore lutescenti, setis glabris; et nervis 
alarum albicantium lutescentibus.” (Hag.) 
Long. corp. ¢ 9-12, ¢ 7-9; set. ¢ im. 15, subim. 
10; set. 2 im. circa 4, subim. circa 3; exp. al. ¢ 23, 
Q 28 mm. 
Hab.—The large rivers of Germany; and at Turin 
(Hag.). July and August. I have taken specimens 
between Cologne and Bonn, in the evening, at the end 
