58 ON A NEW SPECIES OF OLIGONEURIA 
ON A NEW SPECIES OF OLIGONEURIA 
(EPHEMERIDiE) FROM BRITISH EAST AFRICA. 
By Rev. A. E. Eaton. 
Oligoneuria dobbsi, sp. n. 
Adult (dried) ?. — Wings transparent, light blackish-gray, 
with a faint dull violet-purple gloss and intense sepia-brown 
longitudinal neuration ; the cross-veinlets not bordered 
(cf. text-figure). These are numerous (about 80) and straight 
in the marginal area, but are mostly concealed in the dried 
insect so far as the subcosta is overlain in the longitudinal 
furrow in front of the ridge crested by the radius (8) ; the next 
three open areas contain respectively about 15, 7, and 5 cross- 
veinlets, of which many are obsolescent posteriorly, and are 
too delicate to be shown in the figure. The two subfiliform 
tails terminating the narrow membrane incurrent along the 
posterior edge of the mesonotum or scutellum from the roots 
of the fore-wings seem long enough to reach the base of the 
third abdominal segment. Head, body, forelegs, and the 
stout portions of the hinder legs pitch-brown ; head opaque ; 
thorax and dorsum lucid ; venter pallid ; tabescent hind 
tibiae and tarsi impure whitish. Abdomen tapering posteriorly ; 
segments nos. 6, 7, and 8 longer than those anterior to them, of 
which the posterior lateral angles (if not rectangular) are pro- 
duced into only very short, inconspicuous, tooth-like points ; 
but in segments nos. 8 and 9 the points produced are spiniform. 
