46 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.69 



of Natural History; considerable material in the United States 

 National Museum consisting of collected specimens from New York, 

 New Hampshire, Virginia, Maryland, Massachusetts, and Texas; one 

 specimen reared at Monticello, Florida, from Psilocorsis, new species, 

 under Quaintance No. 10577; 11 specimens reared under Gipsy Moth 

 Laboratory No. 12101, from Acrohasis caryivorella Ragonot, taken in 

 Wakefield and Maynard, Massachusetts, and Manchester, Connecti- 

 cut; and tlu-ee specimens from Kenduskeag and Bangor, Maine, reared 

 from Acrohasis hetuleJla Hulst, under Gipsy Moth Lal)oratory No. 

 12406; and at the Gipsy Moth Laboratory, at Melrose Highlands, 

 Massachusetts, a large series of specimens reared from Acrohasis 

 caryivorella and A. hetulella taken at various points in Massachu- 

 setts, New Hampshire, Maine, and Connecticut. 



19. BASSUS USITATLS Gahan 



Bassus usitatus Gahan, Proc. U. S. Nat. Mus., vol. 55, 1919, p. 119. 



Type. — In the United States National Museum. 



Very similar to calcaratus and dijjicilis, the three species being 

 exceedingly close; usitatus, judging by the two known specimens, 

 appears to differ from the other two species in having the second 

 cubital cell much more strongly petiolate, the petiole being distinctly 

 longer than the first radial abscissa; it differs further from calcaratus 

 in possessing red hind trochanters and in the more uniformly dusky 

 hind wings, and from difficilis in the pale apical segment of all 

 tarsi; the value of this last character, however, is doubtful, for in 

 calcaratus the apical tarsal segment varies more or less in color, and 

 this may prove to be true in usitatus and difficilis. Aside from the 

 differences just noted, the characterization of calcaratus given above 

 in the discussion of that species will apply to usitatus. 



Known only from the two type specimens, which were reared from 

 Mineola vacinii Riley at East Wareham, Massachusetts. 



20. BASSUS DIFFICILIS, new species 



Distinguishable from usitatus and calcaratus, its nearest allies, by 

 the characters noted in the key and in the discussion of usitatus. 



Female. — Length, 7.5 mm. Face rather flat, at least as broad as 

 long, smooth; clypeus broad, nearly flat; malar space less than one- 

 third the eye height; eyes large, broad; labial palpi short, the third 

 segment minute, sometimes not distinct; temples not broad, receding 

 gradually; frons pohshod, immargined; ocell-ocular line in the female 

 about twice, in the male less than twice, the diameter of an ocellus; 

 antennae of type 41 segmented; the first flagellar segment not longer 

 than the scape; pronotal pits not margined by carinae; parapsidal 

 furrows sharply impressed, smooth, or only weakly foveolate anteri- 

 orly; middle mesonotal lobe prominently elevated anteriorly; furrow in 



