138 THOMAS SAY FOUNDATION 



Clioperla similis Hagen. 



1861. Perla similis Hagen, Synops. Neur. X. A., p. 26. 



1907. Perla similis Banks, Cat. Neurop., p. 3 2. 



1908. Perla .similis Banks, Ent. Soc. Wash., 9:151. 



Length to wing tips, male, 12 mm., female, 13-15 mm. ; 

 expanse, male, 23 mm., female, 24-28 mm. 



Color brown and yellow with black antennae and yel- 

 low-tipped abdomen. Head yellow around the eyes and 

 beneath and narrowly across the occiput, and paler on the 

 M-mark across the frons, but otherwise blackish dor- 

 sally. Palpi dusky. 



Prothorax much wider than long with bright yellow 

 middorsal stripe, that is variable of width and form, and 

 that is narrowly grooved down its center. This stripe is 

 continued halfway along both meso- and metathorax. Legs 

 dusky. Wings subhyaline with pale brown veins, faintly 

 tinged with yellow at base and at stigma. 



Abdomen brown, the last two segments yellow. Tail 

 brownish, at base yellow. 



Male. Abdominal segments normal to the 8th, which 

 bears a low, broad lobe at its apex, ventrally set off at its 

 base by a curving groove that runs out at the side mar- 

 gins; lobe and sides both yellow. Segment 9 all yellow, 

 abruptly elongated in its lower half into a broadly oval 

 upturned subgenital scoop with a wide obtuse apex. Seg- 

 ment 10 on dorsal apical margin very slightly convex and 

 entire. No genital hooks visible without dissection. Tails 

 thinly hairy, yellow at base. 



Female. Subgenital plate a short broadly rounded lobe 

 occupying the middle half of the border of the 8th ster- 

 nite and overlapping a very little upon the 9th ; the edge 

 in dried specimens appears to be rather evenly truncated. 



Distribution. — Eastern States: Pennsylvania and Mary- 

 land (P. R. Uhler) ; Mt. Washington, N. H., Sept. 14, 

 1907 (Glover M. Allen) ; Moore's Brook near Ithaca, May 

 13, 1922 (C. K. Sibley) ; Ringwood Hollow near Ellis, N. 

 Y., April 17, 1922 (P. W. Claassen). 



Clioperla gravitans, new species. 



(Plate 11, fig. 6; plate 25, figs. 7, 8.) 



Length to wing tips, male, 18 mm. ; expanse, 32 mm. 



Color black varied with yellow. Head black with a pair 

 of irregular longitudinal stripes conjoined across the 

 front ocellus and less broadly behind the epicranial su- 

 ture, separated in front by a narrow yellow median line 

 for the entire length of the clypeus. Eyes narrowly 



