86 THOMAS SAY FOUNDATION 



Abdomen brown, paler toward the base and on the ex- 

 treme apex, darker at the sides ; tails brownish with pale 

 bases. 



Male. Abdominal segments normal to the 9th which is 

 elongate ventrally beneath the 10th in a short subgenital 

 lobe. Segment 10 prominent. Cleft as usual on the mid- 

 dorsal line at the rear, but the angles beside the cleft are 

 produced rearward in a pair of long, flat, backward-point- 

 ing, elongate, subtriangular lobes that are obliquely cut 

 at tips and hairy on rear margins, while their inner edges 

 bear stout pegs in a marginal series. The outer limb of 

 the V-shaped supra-anal process is very long and rises 

 erect from between the lobes of 10 in a thin erect tip with 

 a minute barb on its anterior face near the tip. 



Female unknown. 



Distribution. — Texas ; two males, Austin, Tex., March 

 1, 1903 (J. F. McClendon). 



Male holotype and one male paratype in the Cornell 

 University Collection. 



Perla nona, new species. 



(Plate 17, fig. 21.) 



Length to tip of wings, female 18 mm. Expanse, 32 mm. 



General color black with a conspicuous yellow middorsal 

 stripe. 



Head black with a huge yellow three-rayed spot upon 

 the rear, the middle ray lying within the ocellar triangle, 

 the outer rays out-curving to the eyes ; another large yel- 

 low spot occupying the middle of irons and clypeus; an- 

 tennae and palpi brown. 



Prothorax quadrangular wider than long; convex at 

 front and rear, with a broad median yellow stripe having 

 jagged edges ; median line continued narrowly to the mid- 

 dle of meso- and metathorax and followed on each by a 

 narrow semi-circle, opening forward, pronotum rugose, 

 wings subhyaline. 



Abdomen dark brown ; darker on sides and on apices of 

 segments. Tails somewhat lighter brown. 



Male unknown. 



Female. Subgenital plate low and broadly rounded, 

 covering only the base of the ninth sternite. 



Holotype, female, Corvallis, Oregon (Cornell University 

 Collection). 



