150 THOMAS SAY FOUNDATION 



Female. Subgenital plate normally produced over nearly 

 half of the following sternite, evenly rounded behind. 



Type female, No. 11340, Agr. Coll. Mich. (Banks Col- 

 lection, Mus. Comp. Zool., Cambridge, Mass.). 



Distribution. — 



New York, Ithaca, May 21-June 25; Ringwood 



near Ithaca, May 27, 1919 (K. Dietrich) ; 



Greene Co., June; Clinton, May 24 (P. B. 



Powell) ; Buffalo, July 10 ; Elizabethtown, July 



2, 1923 (P. W. Claassen) . 

 Nova Scotia, Truro, July 7, May 18, 1913 (R. 



Matheson) . 



Isoperla ventralis Banks. 



(Plate 26, figs. 13, 14.) 

 1908. Isoperla ventralis Banks, Psyche, 15:66. 



Length to tip of wings, male, 10-11 mm.; expanse, male, 

 17-19 mm. 



General color dark brown with yellow on head and pro- 

 thorax; wings greenish hyaline. 



Head wider than prothorax; dark brown with a yellow 

 spot in the ocellar triangle and yellow beside the eyes; 

 ocelli connected by a wide V-shaped mark; lateral tuber- 

 cles round, prominent ; frontal ridge low, smooth ; hind 

 ocelli much closer to the eyes than to each other. Anten- 

 nae brown, darker toward the tip. 



Prothorax wider than long, hardly narrowed behind ; 

 front and hind margins rounded ; sides straight ; angles 

 square; a wide median yellow stripe, somewhat con- 

 stricted in the middle ; disc quite rugose, the rugosities 

 dark brown on a yellowish background. Legs brown, 

 tarsi darker. Wings greenish hyaline ; veins heavy brown ; 

 subcosta does not reach the cord ; several costal cross- 

 veins before the end of subcosta and one beyond ; no cu- 

 bital crossvein in hind wing. 



Abdomen brown, lighter at the tip. Tails yellowish at 

 base, darker beyond. 



Male. Ninth abdominal sternite much produced and 

 rounded behind ; eighth sternite with a transverse knob 

 on the hind margin ; subanal lobes sharp, recurved upon 

 the tenth tergite ; supra-anal process not developed. 



Distribution.— Type male, No. 11333, July 28, 1906, 

 Grand Lake, Newfoundland (Banks Collection, Mus. 

 Comp. Zool., Cambridge, Mass.) ; four other males, para- 

 types, from the same locality (Banks Coll.). 



