﻿352 



Fore wing ^ 9 — 12 mm; ? 14 mm. Setæ ^ 34 mm; $ 

 26 mm. 



A small series of males and a single female. The spe- 

 cies has much likeness to Ecdyurus helveticus Etn., but it 

 differs especially with regard to the peculiar markings of 

 the abdominal segments. 



6. Rhithrogena Eatoni n. sp. Thorax light brown. 

 Abdomen dorsally light reddish brown with a pitchy brown, 

 broad, oblique streak at the lateral margin of each seg- 

 ment. The front border of the segments yellowish, and in 

 the front of each of the lateral streaks is a yellowish lunate 

 incision. The hind angles yellowish. The venter yellowish 

 brown, at the apex yellowish red. The forceps brown with 

 the basal joint yellowish red. Setæ brown with small black 

 annulations. Legs yellowish with the fore tibiæ and tarsi 

 darker. All the femoræ with a broad blackish brown middle 

 band (broadest on the fore femoræ) and with a smaller one 

 at the apex. Tarsi with black annulations at the joinings. 

 Wings hyaline. Subcosta and radius yellowish. The other 

 longitudinal nervures and cross veins darker and easily 

 visible. In the pterostigmatical region of the costal area 

 are found about 11 simple cross veins. Length (^ (3 — 6,5 

 mm ; ? 5 — 5,5 mm. Fore wing 6,5- 7,5 mm. Setæ ^ ca. 

 15 mm; $ ca. 11 mm. 



The description is made from a small series of pinned 

 specimens from Vizzavona, where they were collected during 

 the last part of August and beginning of September. I take 

 the liberty to name the species after the Kev. A. E. Eaton, 

 who has the greatest knowledge of the Ephemerida at the 

 present time. 



IV. Plecoptera. 



1. Nemura sp. Five females, captured 25. VIII. 1911, 

 of a species unknown to me. I think it may be best to 

 postpone giving a discription of the species until a male 

 is at hand. 



2. Leuctra Biidtzi ii. sp. Head and prothorax pitchy 



