FI.ECOPTERA OF NORTH AMERICA 63 



Pronotum quadrangular, wider than the occiput and a 

 little wider than long, only slightly narrowed posteriorly ; 

 sides straight, anterior border markedly convex, posterior 

 one a trifle arcuated, anterior angles rather sharp, pos- 

 terior ones rounded ; a broad median yellow stripe, lateral 

 fields embossed. A similar, broad median stripe on the 

 metanotum, and a small median marginal spot, on the an- 

 terior border of the metanotum. Venter of thorax pale 

 with a median shield-shaped darker marking on each of 

 the three segments ; from these dark median spots on the 

 last two segments, transverse extensions run out laterally 

 just anterior to the base of the legs. Legs yellowish- 

 brown, bases and tips of femora and tibiae, and tarsi, 

 dark brown. Tips of wings broadly rounded, venation 

 pale brown ; a rich irregular network of crossveins be- 

 tween costa and the anterior branches of the sector, in the 

 fore-wing there is not a long costal area beyond the 

 humeral crossvein that is free from crossveins, subcosta 

 passes into radius slightly beyond the level of the cord, 

 the length of the inner inter-radial cell twice as great as 

 its base, first anal vein forked (PI. 7, fig. 23). 



Female. Abdomen brown above and below; subgenital 

 plate paler, large and shining, produced nearly across 

 segment nine ; the posterior border in the form of a W 

 with rounded angles (fig. 49). 



Distribution. — California; the single known specimen 

 (female type) is without more specific designation of lo- 

 cality. 



Perlodes ignota Smith. 



(Plate 7, fig. 22.) 

 1917. Arcynopteryx ignota Smith, Trans. Amer. Ent. Soc, 43:479. 



The following is the original description : 



Female. Length to tip of wings, 17 mm. ; expanse of 

 wings, 29 mm. 



Dark brown, with a few paler markings. Head triangu- 

 larly produced ; three moderately large ocelli arranged in 

 an isosceles triangle, the base of which is greater than the 

 sides, but less than the distance from the posterior ocelli 

 to the inner margin of the eyes; the M-shaped mark 

 present but not prominent, small, round, inconspicuous 

 tubercles situated nearer the posterior ocelli than the in- 

 ner margin of the eyes. The lateral borders of the clypeus 

 pale yellow; a dark fuscous crown spot in the form of a 

 letter X with its center in the median ocellus, the anterior 

 part outlining the middle region of the M and the 

 posterior part extending back to the lateral ocelli; a 



