PLECOPTERA OF XORTH AMERICA 257 



segments, longer than entire body ; middle segments at 

 least five times as long as wide. 



Male. Abdominal tergites smooth, without any knobs, 

 covered with long hairs ; ninth tergite with a narrow me- 

 dian depression ; tenth tergite bifid ; supra-anal process 

 recurved, slender, tapering to a sharp point and reaching 

 above to hind margin of eighth (normal position) ; the 

 supra-anal process is grooved ; subanal lobes upcurved 

 and bluntly pointed ; ninth sternite somewhat produced 

 and evenly rounded behind. 



Female. Eighth abdominal sternite unmodified and 

 not produced into a subgenital plate. 



The above description pertains to the specimens which 

 have been collected in New York State. Specimens from 

 Michigan agree in general structural details but they are 

 of a brown color instead of black and emerge much later. 

 They are placed here with some doubt. 



Distribution. — Originally described from specimens col- 

 lected at St. Martin's Falls, Albany River, Hudson Bay 

 (Barnston). Many specimens from Mountain Lake, Fulton 

 Co., N. Y., April 26, 1923 (P. W. Claassen) ; Clinton, N. Y., 

 March, 1903 (P. B. Powell) ; Highland, N. Y., March 12, 

 1919 ; Gilman Lake, Fulton Co., N. Y., April 27, 1923 (P. 

 W. C.) ; Coy Glen, Ithaca, N. Y., March 30 ; Isle Royal, 

 Mich., July 14, 1905 (H. A. Gleason). 



This is the only species of the genus found east of the 

 Rocky Mountains. 



Capnia nana Claassen. 



(Plate 48, fig. 3.) 

 1924. Capnia ncna Claassen, Can. Ent., 56:46. 



Length to tip of wings, male, 5.5 mm. Expanse, male, 

 7 mm. Length to tip of abdomen, male, 6.5 mm. 



General color blackish. Head wider than prothorax, 

 black; ocelli small, the hind ocelli nearly three times as 

 close to eyes as to each other; antennae blackish. Pro- 

 thorax about as long as wide, blackish ; sides nearly 

 straight; angles rounded; surface somewhat rugose, es- 

 pecially toward the center. Legs blackish brown. Wings 

 subhyaline, not reaching to the tip of the abdomen ; R in 

 forewing bent upwards at origin of Rs; Rs-M stem of 

 hind wing very short. Abdomen blackish ; cerci with 

 more than ten segments (tips broken off) . 



Male. Eighth abdominal tergite with a small median, 

 raised, chitinized process ; ninth and tenth tergites with 

 a median depression ; supra-anal process recurved, short, 



