166 THOMAS SAY FOUNDATION 



Abdomen whitish poninose, with the usual tessel- 

 lation and three changeable black stripes; first and 

 second segments with only lateral bristles; the third 

 with an interrupted row of ten ; the fourth with a row 

 of about 14. 



Hypopygium black; first segment pollinose, 

 wdth erect hairs but no bristles; second segment shin- 

 ing, with numerous erect hairs; forceps black, long 

 and broad, with dense long black hair on basal part; 

 the free part is tapering and gently curved forward 

 in profile to a sharp point, with a small tooth on it. 

 Viewed from behind, they are readily distinguishable 

 from all other species by being deeply grooved, espe- 

 cially on the apical half. The groove is broad, so it is 

 only bordered by a narrow elevated ridge on each 

 side ; the points are widely divergent. Accessory plate 

 rather slender, posterior clasper brown, slender, 

 curved, sharp at tip; anterior clasper very similar in 

 shape; penis with rather short basal joint, distal sud- 

 denly expanded into a globose structure, at the end 

 of which on the back part there arises a round, tubu- 

 lar prolongation, ending in two long plates reaching 

 forward and lapping over each other; between these 

 there arises a soft, slender, pale process; the globu- 

 lar central mass also bears on its front apical side two 

 flat plates side by side, which are bent into strong re- 

 curved hooks, and basally from these on each side 

 there is a slender rolled up transparent plate; fifth 

 sternite very much retracted. 



Legs black; middle femur with a rather well de- 

 veloped comb on the hind edge below; middle tibia 

 with one bristle on outer front side; hind tibia with 

 rather dense, long villosity, spreading both ways. 



Wings almost hyaline; no costal spines; third 

 costal segment longer than the fifth and sixth to- 

 gether; first vein bare; second hairy for two-thirds 

 the distance to the crossvein. 



Length 8 mm. 



One male, Gypsy Moth Laboratory, Melrose 

 Higlilands, Mass.,"May 13, No. 1400. "Reared from a 



