BANKS: m.\\ \i i ROFl EROID [NSECTS. 31 - 



qoetanotum pale; abdomen pale, brown toward tip; sternum and venter pale; 

 le^- pale brownish, tips of tarsi darker. Wings brown, costal area, especially 

 Hi' the hind wings, darker than elsewhere, venation dark brown. Posterior 

 ocelli a little nearer to the eyes than to each other, ocellar triangle broader 

 behind than long; lateral bosses slender, transverse, appearing to reach in a 

 curved line toward the posterior ocelli; pronotum one and one third broader 

 than long, rather narrower behind, sides parallel, anterior edge convex; setae 

 rather short. Radial Bector three-branched, four cross-veins beyond end of 

 the Bubcosta, anastomosis continuous, seven to nine median and cubital 

 cross-veins; the male shows on both seventh and eighth ventral segmenl a 

 small median process. 

 Ebcpanse 23 nun. 



Perla subvarians, sp. now 



Type.— M. C. Z. 10,817. Va.: Great Falls. Md.: Great Falls, 

 High Island, L5 April to 12 May. 



This species is what I have recorded as P. varians in the Washington list. 

 It is similar in many ways to that species, but on comparison with types of 

 Walsh's species it differs in several points. The ventral plate of the female is 

 more triangular, and longer in the middle, the pale median spot on vertex of 

 head in both is in P. subvarians continued forward as a narrow streak into the 

 ocellar area, the stripe on thorax is more narrow, and the posterior ocelli are 

 nearer to each other than in P. varians although still a little nearer to the eyes 

 than to each other; the pronotum is proportionally a little longer than in 

 P. varians. 



Expanse 38 mm. 



Perla expansa, sp. nov. 



Type.— M. C. Z. 10,816. Col. : Grant, 1G August (E. C. Jackson). 



Black; head with a very broad reddish yellow median stripe, interrupted 

 only at the anterior ocellus by a narrow transverse black band; pronotum 

 with broad median stripe pale; last segments of the abdomen pale brownish; 

 setae pale brown. Wings slightly infuscated, the veins (except costals) dark 

 brown: radial sector three-branched, two cross-veins beyond end of the sub- 

 costa, about six median and cubital cross-veins, second anal vein curved. 

 Posterior ocelli much nearer to the eyes than to each other, the ocellar triangle 

 much broader behind than long, lateral bosses transverse, not far from posterior 

 ocelli; the pronotum one and one third broader than long, sides nearly parallel ; 

 female ventral plate extremely large, rounded, and convex. 



Expanse 32 mm. 



Very similar to Perla modesta, also from Colorado, but the ventral 



plate is very much larger; and the venation much darker. 



