98 



NATHAN BANKS. 



Order ARCHIPTERA. 



Suborder PLECOPTERA 



Family PERLID.E 



Aci'oueuria nigrita n. sp. — Black; head rather yellowish; antennae 

 brown ; pronotum brown, a pale stripe in middle; thorax shining black, abdomen 

 dull black ; legs and setae brown ; wings with blackish veins. Pronotum in front 

 about as wide as head, narrowed behind, sides straight, surface moderately ru- 

 gose. Venation about as usual, but there are not as many branches of the radial 

 sector beyond anastomosis as in other species (although this is variable). Ven- 

 tral plate of female with a long deeply incised mark at tip, not seen in other 

 forms. Length 21 mm. ; expanse 54 mm. 



Two females from Pecos, June (Cockerell). One micropterous 

 male from the same locality probably belongs to this species, but is 

 much smaller. 



Pteronarcella badia Hagen. 



Four specimens from Pecos, June (Cockerell). 

 Isogeuiis elongatus Hagen (?). 



One female of an Isogenus which does not appear to differ from 

 this species, Pecos, June. 



Perlinella obria Hagen. 



From Las Vegas, June (Cockerell). 

 Perlinella frontalis Eauks. 



One from Beulah, May 30th (Cockerell). 



