

PLECOPTERA OE NORTH AMERICA 179 



1907. Acroncuria dbnormis Banks, Cat., 10. 



1908. Acroneuria dbnormis Banks, Proc. Ent. Soc. Wash., 11:150. 



1909. Acroneuria dbnormis Klapalek, Bui. Acad. Bokeme, 14:5. 

 1922. Acroneuria dbnormis Needham and Claassen, Can. Ent., 54:252. 

 1851. Acroneuria sonans Newport, Trans. Linn. Soc. Loudon, 20:447. 



Length of wings, male, 25-28 mm. ; female, 32-42 mm. 

 Expanse, male, 46-50 mm. ; female, 54-70 mm. 



General color light brown. Head wider than prothorax, 

 yellowish with a dark spot over the front part of the 

 ocellar triangle, and extending laterally toward the an- 

 tennae; usually a pair of triangular dark spots on head 

 behind the ocelli, pointing inward ; clypeus brown ; frontal 

 M ridge wide, yellow; lateral tubercles flat, yellow. An- 

 tennae brown. Ocellar triangle nearly equilateral, the 

 hind ocelli half again as close to each other as to the 

 eyes. 



Prothorax wider than long, narrower behind ; front and 

 hind margins rounded; sides nearly straight; front angles 

 sharp, hind angles subacute; surface not very rugose; 

 median line not very distinct. Legs yellowish, femora 

 with a broad blackish transverse band just before the dis- 

 tal end ; tibia with a dark band at base ; tarsi dark. Wings 

 uniformly subhyaline ; veins brown ; numerous crossveins 

 beyond the cord distributed more or less evenly across the 

 entire radial-median area. 



Abdomen pale yellow above and underneath; sides 

 somewhat darker. Cerci or tails brown, yellow at base; 

 closely covered with short hairs. 



Male. Ninth abdominal sternite with a transverse, 

 oval, smooth hammer; subanal lobes broadly triangular, 

 sharp and reaching to about the middle of the tenth ter- 

 gite ; tergites 9 and 10 each with a large number of short 

 spines. 



Female. Eighth abdominal sternite very slightly pro- 

 duced into an unevenly rounded subgenital plate. The sub- 

 genital plate varies in different individuals from an al- 

 most truncate plate which is not at all produced to an 

 evenly rounded plate produced over a third of the ninth 

 sternite. 



Distribution. — 



New York, Ithaca, June 5 to Aug. 27; Green Co., 

 June; North Creek, July 4, 1918; Keene Val- 

 ley, Essex Co., June 28, 1895 ; Oswegatchie. 



North Carolina. Black Mts., July 1-Aug. 30, 1912, 

 Beutenmiiller. 



Maryland. Glen Echo, May 29, 1899 (R. P. Currie). 



