PERLA. 17 



the maxillary palpi : it is, however, of doubtful importance. The 

 species, perhaps, is P. biloba. 



* * Wings with few, but rather regular, transverse 

 veins. 



PERLA GEOFFEOT. 



Wings veiny, transverse veins few, very regular; posterior wings 

 with the anal space large, plicated ; palpi setaceous ; two caudal 

 setas. 



O The submarginal, apical space of the anterior wings 

 with some transverse veins. Subgenus Acroneuria 

 Pictet. 



1. P. abnormis ! 



Perla abnormis Newm.! Entom. Mag. V, 177. Pict. Perl. 180, 12. Walker! 

 Catal. 147, 21. P. arenosa Pict.! Perl. 178, 11; tab. x, fig. 12. 

 Walker, Catal. 147, 19. P. pennsylvanica Ramb.! Neuropt. 456, 13. 

 -P. internata Walker! Catal. 152, 41. P. trijuncta Walker! Catal. 

 153, 43. P. sonans Barnston, Newport, Linn. Trans. XX, 447. 



Yellowish-fuscous; the head broader than the prothorax, luteous, 

 obscure in the middle ; the antennas fuscous,' the second articulation 

 and sometimes the following ones luteous; prothorax narrower 

 posteriorly, the angles acute, sides straight, surface rugulose, the 

 middle line scarcely more distinct ; the feet luteous, knees fuscous ; 

 abdomen beneath yellowish, setas fuscous, densely pilose; g last 

 ventral segment large ovate, with a round, polished spot ; ' 9 ante- 

 penultimate ventral segment slightly rounded, produced; wings 

 subhyaline, veins clay-yellow; the vein accessory to the subcosta 

 four-forked, some transverse veins. 



Length to tip of wings, ^ 27 ; 9, 35 millim. Alar expanse 

 c? 50; 9, 60 millim. 



Hob. St. Lawrence River (Barnston) ; Philadelphia, Pa. (Pic- 

 tet) ; Trenton Falls (Osten Sacken) ; Georgia (Abbot) ; South 

 Illinois (Robt. Kennicott) ; Maryland (Uhler). 



I have seen a specimen from Mexico (Muehlenpford, in the 

 Berlin Museum), which was paler, with many transverse veins, 

 and the antepenultimate segment produced elliptically. Is it a 

 distinct species ? 



