518 WILLIAM T. M. FORBES 



3. Sexes similar; male with rounded hind wings; female with simple or 

 laminate antennae 2. Acossus. 



3. Sexually dimorphic; male with outer margin of hind wing nearly straight; 

 female with pectinate antennae 3. Prionoxystus. 



Subfamily HYPOPTINJE 



Smaller species, the larvae probably normally in roots of perennial herbs; moth 

 tending strongly to lose tibial spurs and frenulum. A strong cross-vein near outer 

 margin, between 1st A and 2d A; other characters as in Cossinee; larva not well 

 known. 



1. GIVIRA Walker 

 (Inguromorpha; Hypopta, in part) 



Male antennas pectinate to apex, in female normally very narrowly pectinate; 

 palpi moderate, upturned; accessory cell small, but well set off from discal cell; 

 intercalated cell inconspicuous. Hind wing with R t rudimentary, R 8 and MI 

 stalked. Vestiture spatulate. 



1, G. anna Dyar. Gray, evenly recticulate with lines of black powdering, discal 

 lunule white; inner margin narrowly white at base. Hind \ving darker, unmarked. 

 25 30 mm. 



Florida; St. Louis, Missouri; and probably in intermediate country. 



The St. Louis race is darker than the type. 



Subfamily COSSINJE 



Egg upright; strongly ribbed; with well marked micropyle. Larva with cervical 

 shield moderate and smooth, spiracles in line; crotchets in our two genera trior- 

 dinal, in a complete circle; in the genus Cossula (which is transitional to the 

 preceding subfamily) crotchets uniordinal in two transverse rows. Pupa with 

 maxillae not meeting in middle line beyond end of labial palpi; maxillary palpi 

 separately chitinized; head smooth. Imago with male antennae pectinate to apex, 

 or entirely simple, laminate; palpi moderate; intercalated cell triangular, normal; 

 1st A and 2d A free; hind wing with R and Mj connate or stalked; M 2 , M 3 , and 

 CUj more or less approximate. 



2. ACOSSUS Dyar 

 (Trypanus, Cossus, in part) 



Vestiture of thorax deep, spatulate, but regularly imbricated, with posterior 

 tuft; male antennae pectinate to apex; female antennae laminate below; palpi 

 moderate, upturned. Fore wing with large accessory cell; Rj arising from discal 

 cell, R 2 from accessory cell, R 3 connate with R 4+3 , which are stalked less than half- 

 way to apex. Intercalated cell triangular, not reaching posterior margin of discal 

 cell; anals not connected. Hind wing relatively large, with Sc and R connected 

 by a strong vein about two-thirds way out on cell; R and M t shortly stalked; 

 M 2 , M 3 , and Cu x approximate at base. 



1. A. centerensis Lintner. Thorax and basal half, or rather more, of fore wing 

 blackish; collar often partly light gray; thorax spotted with whitish. Outer 

 part of wing contrasting, pale gray; the whole wing dusted and heavily reticulate 

 with black. Hind wing translucent, very lightly reticulate, with blackish fringe. 

 Hair in base of anal region blackish. 50-60 mm. (H 12:1.) 



Larva boring in poplar. Tubercle iii of metathorax fully as large as ii 



