130 THOMAS SAY FOUNDATION 



Distribution. — Western States. 



Genotype, Perlinella frontalis Banks. 



This genus is represented by only one species. By its 

 long head and transversely oval prothorax, as well as by 

 other characters it is allied to Kathroperla Bks. 



Paraperla frontalis Banks. 



(Plate 15, fig. 8; plate 23, figs. 4, 5, 6.) 

 1902. Perlinella frontalis Banks, Can. Ent., 34:123. 

 1907. Paraperla frontalis Banks, Can. Ent., 39:328. 

 1907. Paraperla frontalis Banks, Cat. Neurop., p. 12. 



Length to tip of wings, male, 11-14 mm. ; female, 13-17 

 mm. Expanse, male, 20-25 ; mm. ; female, 22-28 mm. 



General color brown. 



Head slightly wider than prothorax; yellowish with a 

 darker spot over the ocellar triangle; bounded behind by 

 the occipital sutures and enclosing the large flat lateral 

 tubercles, extending forward nearly to the front margin 

 of clypeus ; frontal ridge shaped like a German capital V ; 

 the area just back of eyes and the posterior border of the 

 head brown; length of head behind the eyes at least as 

 long as the length of the eye; the ocelli form an almost 

 equilateral triangle, the hind ocelli being a little closer to 

 each other than to the eyes ; apical segment of maxillary 

 palpi small ; antennae dark brown. 



Prothorax transversely oval, wider than long, some- 

 what narrowed behind ; all angles very broadly rounded ; 

 brown with a lighter area on each side and with the ru- 

 gosities darker brown ; a narrow median longitudinal 

 black line and a narrow black line within the groove 

 which extends around the entire margin of the pronotum. 

 Legs brown ; femora with a narrow transverse black band 

 at the tip and tibiae with a black spot at the proximal end ; 

 tarsi blackish, first and second segments short, subequal, 

 third segment at least twice as long as one and two com- 

 bined. Wings subhyaline, veins heavy, brown ; subcosta 

 ends much before the cord; four to six costal crossveins 

 before the end of subcosta and three to four beyond ; 

 radial sector with two or three branches ; second anal 

 vein of f orewing forked ; hind wing with a large anal 

 field, with several cubital crossveins; basal stem of Rs-M 

 in hind wing very long. 



Abdomen brown. Setae yellowish brown to dark brown ; 

 long, with at least 18 segments ; middle segments about 

 four times as long as wide. 



Male. Ninth abdominal sternite slightly produced and 

 evenly rounded behind ; tenth tergite cleft ; supra-anal 

 process upturned, largely membranous and composed of a 



