104- THOMAS SAY FOUNDATION 



Head very little wider than prothorax ; frontal ridge, 

 lateral tubercles and occiput yellowish, rest of surface 

 mostly black, deepest black over the ocellar triangle ; 

 lateral tubercles large, prominent ; hind ocelli closer to 

 each other than to the eyes ; antennae brown at base, 

 darker towards the tip. 



Prothorax dark brown to blackish ; wider than long, 

 much narrower behind; front angles acute, hind angles 

 obtuse; surface quite rugose, the rugosities often lighter 

 brown. Legs brown. Wings subfumose, veins brown; 

 subcosta ends at the cord ; a series of costal crossveins 

 before the end of subcosta and beyond. 



Abdomen yellowish, tails yellowish to brown. 

 Male. Abdominal tergites 1 to 4 normal, the fifth pro- 

 duced backward into a bilobed process with a broad shal- 

 low emargination between the lobes which are beset with 

 many prickles ; tergites 7, 8 and 9 partly membranous 

 above and medially beset with many prickles ; the tenth 

 tergite bears a pair of genital hooks, as shown in Plate 

 19, figure 4 ; ninth abdominal sternite somewhat produced 

 behind and evenly rounded ; abdominal sternites 2-8 beset 

 with stiff hairs which are thickest on segments 3-6. There 

 is also a heavy patch of stiff hairs on the metasternum 

 and some on the mesosternum. Subanal lobes unmodified. 

 Female. Hind margin of eighth sternite medially some- 

 what produced into a bilobed subgenital plate, as shown 

 in Plate 19, figure 5. 

 Distribution. — 



Quebec, Saguenay River, July 25, 1906 (George 



P. Englehardt) ; Ottawa, Sept. 7. 

 New York. Ithaca, May 31-July; Niagara Falls, 

 July 12 and July 6 ; Crane Pond, June 25, 1897 ; 

 Oswego, June 21, 1894; Fulton, June 20, 1890; 

 Wilmurt, Herkimer Co., June 10 ; Ogdensburg, 

 July 16, 1906 ; Buffalo, July 9, 1906. 

 Minnesota, Minneapolis, May 25, 1922 (William 

 E. Hoffman). 



Genus ALLOPERLA Banks. 



1906. Alloperla Banks, Ent. News, 17:175. 



1907. Alloperla Banks, Cat. Neurop., p. 13. 



Small yellowish or greenish species, eight to fifteen 

 mm. long ; with three ocelli ; pronotum transversely oval 

 or with very broadly rounded angles ; second tarsal seg- 

 ment very short; wings yellowish to greenish. Head not 

 much wider than prothorax ; hind ocelli not much closer 



