568 Mr. Kenneth J. Morton on 
Nemoura Meyert. 
N. Meyeri, Pictet, Perlides, p. 390, pl. h. 
Head and thoracic segments black, antenne blackish, hind-head 
and margins of pronotum usually yellowish, the latter segment 
about same breadth as head with very slightly rounded margins 
(the material examined shows great variation in the form of the 
pronotum). Legs yellowish, middle and apex of femora, apex of 
tibiz and tarsi blackish. Wings greyish, often whitish, most of 
the nervures broadly bordered with brownish grey, or the colour 
might be given as brownish grey with white spots ; pterostigma 
pale in the middle and dark on either side; neuration blackish, 
extreme end of radius upturned, lower branches of sector and 
superior cubitus usually much curved. The most characteristic 
feature of the ¢ genitalia is a pair of long upturned spine-like 
sheaths. The large upturned pieces behind these sheaths appear 
to be flanked by blackish pectinated pieces which are often con- 
cealed. Exp. ¢, 153-183 mm.; 9, 183-24 mm. 
In what may be termed typically marked examples, 
this species may be easily recognised by the two-coloured 
pterostigma, the curved neuration above alluded to, and 
the marking on the middle of the femora is also of im- 
portance. With regard to the genitalia of the 3, confusion 
is possible with N. marginata; in the latter species, 
however, the ‘‘ upturned spine-like sheaths” are not 
usually so straight and they end in two points, and the 
pectinated pieces are much more conspicuous and have 
much longer teeth than in Meyert. Well-marked ex- 
amples of the species are usually correctly named. 
I can say little regarding the geographical distribution 
of this species. It is rather common at many streams in 
North Britain in May and June, and even later in 
localities of some altitude. It is also represented 
by large examples from Carinthia in the collection 
of Mr. McLachlan and from Switzerland in that of 
Dr. Ris. 
Under the name of WN. nitida, Pictet, Professor 
Klapalek has communicated a pair of Bohemian insects, 
the ¢ immature and the ? closely resembling N. Meyerv. 
The paired spines are not unlike those of the species 
hereafter described as N. marginata; they appear to be 
shorter and broader before the apex than in N. Meyeri, 
and terminate in two more or less divergent spines. ‘This 
