OF NATURAL IIISTOIIV 73.] 



the neuter abdomen if^ mure reniarkublc than that .>f the female. 

 It probably belongs to the genus Polycnju*. 

 A variety is much paler, even honey-yt'llow. 



5. F. TRIANGULARIS. — IViHCoidal ccllulf sul)triaiiL,Miliir ; black- 

 ish-piceous. 



Inhabits Indiana. 



IJody black ish-piceous or obscure rcddisb-browii : livp«»stnni:i 

 convex and somewhat carinatc : mandibles piccoua : wingn whit- 

 ish; ncrvurcs pale ; discoidal crllulc pubtrianjrular, the su|)criur 

 angle being very obtuse ; first and second cubital celluica not 

 separated by a petiole ; anal nervure abruptly angulated on the 

 anal submargin : scale rather thin, elevated : tarsi honey-yellow. 



% Hody darker. 



Length 9 over one-tenth of an inch ; % about the same. 



Var. a. Recurrent nervure none. 



Var. P. Recurrent niTVurc obsolete or incomplete. 



Resembles scssilis nob., but the scale is obvious; the diseoidal 

 cell is more triangular and the nervure of the second cubital \^ 

 obvious. 



1). F. DISLOCATA. — Yellowish; anal nervure almost dislocated 

 at the anal eniargination. 



Inhabit*} Indiana. 



Head black : hypostoma distinctly carinated : front [289] with 

 an acute, longitudinal, elevated line over the insertion of each 

 antennae and a slightly impressed line in the middle : anteniisc 

 and mandibles piceous : thorax honey-yellow, dusky before : 

 wings tinged with fuliginous; ncrvurcs dusky and very distinct ; 

 recurrent nervure forming a quadrate cellule less than half the 

 size of the first cubital ; anal nervure abruptly angulat^^d near 

 the anal emargination of the edge, and almost dislocated in that 

 part, the terminal portion being arcuated at each extremity : pcale 

 thick, prominent, obtupe, entire : abdomen blacki-h, with pro-- 

 tratc hairs, and sparse elevated ones and regular c'lWsv. on the 

 edges of the segments; first segment honey-yellowish at btac, 

 without any indentatit)n opposite the scale : feet honey-yellow. 

 I Trunk and scale entirely pale honey-yellowish : scapu* of 



1836.] 



