8 
ESBEN-PETERSEN. 
5th segments; on the 6tli to 8th segments they become gradually narrower, and on the 
9tb to 10 th tliey are indistinct. Uuderside of the body rieh yellow. Setae yellowish white 
with narrow, slightly reddish annulations at the joinings. Legs yellow; claws yellowish 
grey. Anterior femora with two purplish red bands, one in the middle and one at apex. 
Middle and hind femora with an indistinct brownish red ring towards apex. Wings hyaline 
with yellowish tinge. Fore wings in the marginal and submarginal areas tinged with ricli 
yellow; in the pterostigmatic région the yellow colour has a reddish tint. The marginal 
area, in the hind wings, only tinged with yellow at the base. Longitudinal nervures light 
greyish yellow; the cross veins dark greyish yellow in the fore wings, paler in the hind 
wings. In the fore wing, in the middle of subcosta, is a larger, conspicuous, oblong, dark 
dot. A smaller one is placed just behind it on the subradius. 
Length 12 mm.; fore wing 15,5 mm.; setae 20 mm. 
In the collection was a fcmale, preserved in alcohol, taken the 31. VIII. 1909 at the 
Obi river (Sango-pan). 
Besides tliis one I hâve seen a $, collected by Mr. Basile Bostanjoglo in a valley at 
the Volga, near Moscow, 8. VI. 1909. The description is given from the last named specimen. 
It is a fine and conspicuous species, easily recoguized by its strongly pronounccd 
purplish red colour and by the two dots on subcosta and subradius. 
B. Larvae. 
Baëtis sp. I. 
Nymph. Light reddish brown. Head and thorax, with a fine pale médian line. A few 
darker spot are visible on the upper side of thorax and abdomen. Underside unicolourous. 
Femora slightly darker than tibiae and tarsi. Middle seta most often the shorter. Autennae 
dark at the base, paler towards apex. Length 7—8 mm.; setae 5 mm. Several specimens 
present. 
Fig. 10. Hrtêtiss Inrva I. a Labium, b left inaudible, c left maxilla. 
