PLECOPTERA OF NORTH AMERICA .55 



2. Its palpi are dark brown, not pale yellow. 



3. Its pale crown spot between the ocelli is larger and 

 not confluent with the yellow of the rear of the head. 



4. Its femora are blackish (except knee ring) , not pale 

 brown. 



5. Its prothorax is clothed with yellowish hairs. 

 Female unknown. 



Distribution. — Olympic Mountains, Washington. 



The shrivelled condition of the end of the abdomen pre- 

 vented a critical study of the male genitalia of the type. 

 The venation is quite like that of P. dolobrata, and the 

 sides of the prothorax are similarly convergent to rear- 

 ward. Abundant crossveins in the cubital area of the 

 tip of the forewing seem to ally this species with P. dolo- 

 brata rather than with P. bradleyi. 



Perlodes signata Hagen. 



(Plate 9, figs. 7, 8; plate 4, figs. 6 to 10; plate 10, fig. 3.) 

 1873. Dictyopteryx signata Hagen, Bull. Geol. Surv. Terr., p. 575. 

 1903. Perlodes signata Banks, Ent. News, 14:241. 

 1912. Megarcys signata Kip., Coll. Zool. Selys, 4:12. 

 1917. Megarcys signata Smith, Trans. Am. Ent. Soc, 43:472. 



Male. Length to tip of wings 20 mm. Expanse 30 mm. 



Female. Length to tip of wings 25 mm. Expanse 

 42 mm. 



Color brownish, varied with yellow. Sides of head and 

 thorax darker than the dorsum. Middorsal pale stripe 

 rather conspicuous. Transverse pale M-line across the 

 frons inconspicuous. Another M-line in brown subtends 

 it in the rear, enveloping the front ocellus and running 

 rearward in a pair of diverging lines to the posterior 

 ocelli, and thus surrounding the pale spot on the crown. 

 There is a roundish median occipital spot of yellow, often 

 connected by a narrow median line with the crown spot, 

 bordered on either side by an anvil-shaped spot of brown 

 whose long point extends obliquely forward along the 

 frontal suture. Eyes surrounded by yellow internally, 

 and followed by a brown spot that covers the hind angles 

 of the head. In pale specimens these markings are often 

 very obscure. Antennae and palpi yellowish brown. 



Prothorax quadrangular, a little wider than long, a 

 little narrower than the head. Middorsal stripe yellow, 

 broad, slightly widened posteriorly and often divided by 

 a narrow median single or broken or double or otherwise 

 irregular line of pale brown. Brown raised marmorations 

 thickly besprinkle the sides of the disk, closely crowded 



