11*2 THOMAS SAY FOUNDATION 



Alloperla lateralis Banks. 



(Plate 21, figs. 6, 7.) 

 1911. Alloperla lateralis Banks, Trans. Am. Ent. Sop., 37:337. 



Length to tip of wings, male, 9.5-11 mm.; expanse, 

 male, 17-20 mm. ; length to tip of wings, female, 10.5-13 

 mm. ; expanse, female, 20-23 mm. 



General color yellowish with a narrow black margin 

 around the pronotum. Head hardly wider than pro- 

 thorax; pale yellowish with a little black around the 

 ocelli ; frontal ridge and lateral tubercles weak ; hind 

 ocelli a little closer to the eyes than to each other; an- 

 tennae yellowish at base becoming dark towards the tip. 



Prothorax transversely oval, almost twice as wide as 

 long; pronotum with a narrow blackish margin all 

 around ; surface somewhat rugose, the rugosities a little 

 reddish or brownish. Legs yellow, tarsi a little darker. 

 Wings yellowish or greenish hyaline; veins greenish yel- 

 low. 



Abdomen yellowish, with a broad blackish median dor- 

 sal stripe. Cerci yellowish, a little darker towards the tip. 



Male. Tenth abdominal tergite broadly and deeply 

 cleft, the lobes each side bearing long hairs ; ninth ter- 

 gite much depressed posteriorly and on the anterior 

 margin with two raised rounded knobs or tubercles; su- 

 pra-anal process recurved, long and slender with the tip 

 turned up ; subanal lobes small, unmodified ; ninth sternite 

 produced and truncate behind. In its normal position the 

 tip of the abdomen is somewhat turned up and tergites 

 eight, nine and ten are telescoped together with the su- 

 pra-anal process completely hidden in the cleft portion of 

 nine and ten. 



Female. Subgenital plate of eighth abdominal sternite 

 narrowly and triangularly produced so that normally the 

 tip of the plate extends to the tip of the abdomen ; plate 

 normally with a median longitudinal ridge. 



Distribution.— -Type, female No. 11354, May, Black Mts., 

 N. C. (Banks Coll., Mus. Comp. Zool., Cambridge, Mass.) ; 

 cotypes, three females, one male, same locality as type ; 

 one male, one female, June 13, Gloversville, N. Y. ; two 

 females, June 25, Woodworth Lake, Fulton Co., N. Y. — 

 All in Banks's Coll. Four males, May 20-25, 1911, Black 

 Rock Mt., Raban Co., Ga. (J. C. Bradley) ; males and fe- 

 males, May and June, Ithaca, N. Y. ; one female, June 10, 

 De Ruyter, N. Y. ; one female, June 23, 1910, Woodworth 

 Lake, Fulton Co., N. Y. (C. P. Alexander) ; two males, 

 June 13, 1910, Gloversville, N. Y. (C. P. A.) ; males and 

 females, June, Danby, N. Y. ; one female, June 12, Ram- 



