PERLIDES. 147 



19. PERLA ARENOSA. 



Perla arenosa, Pictet, Hist. Nat. Neur. Perl. 178, 11, pi. 10, f. 1, 2. 

 North America. 



20. PERLA PENNSYLVANIA. 



Perla Pennsylvania, Ramb. Hist. Nat. Ins. Neur. 456, 13. 

 Philadelphia. 



21. PERLA ABNORMIS. 



Fusca, fere concolor ; alee fuscescentes, superne apicibus relicu- 

 latce. 



Perla abnormis, Neivm. Ent. Mag. v. 177. Pictet, Hist. Nat. Neur. 

 Perl. 180, 12. 



a. Trenton Falls. Presented by the Entomological Club. 



Group 4. PERLA. 



Alae apud stigma non maculatae. Vena subcostalis accessoria 

 simplex, aut regulariter unifurcata vel bifurcata. Areola marginalis 

 apicalis venis duabus aut pluribus transversis. 



Perla, Pictet, Hist. Nat. Neur. Perl. 144, 4. 



Terminal part of the submarginal region without cross veins ; 

 accessory vein of the subcostal vein without ramifications, or with 

 one or two regular bifurcations ; marginal terminal areolet with at 

 least two transverse veins. Species of a large or middle size, of a 

 more or less deep brown or yellowish colour. 



Sub-group 1. 



Species plus minusve obscure fuscae, magnae vel mediocres. 

 Prothorax lateribus rectis angulisque acutis. Ala? subfusca? vel 

 subfulvae, venis robustis. 



Species of large or moderate size : prothorax with straight 

 sides and sharp angles : wings with a brown or a tawny tinge, 

 strongly veined : general colour more or less deep brown. 



02 



