334 ERNEST A. BACK. 



Sticliopogon argenteus. 



Dasypogon argenteus Say, Jour. Acad. Sci. Phila., Ill, 51, 1822; 

 Compl. Works, II, 65. 



Dasypogon argenteus Wiedemann, Auss. Zw., I, 409, 1828. 

 r? 9- — Length 6—8.5 mm. — Black, but wholly silvery-white pruinose; 

 pile and weak bristles entirely white. This is a smaller insect than 

 trifasciatus and much more pilose. The mystax is more abundant 

 and extends upward somewhat on the face; the pile on the basal seg- 

 ments of the black antenna? and along the frontal orbits is very fine. 

 Occipital bristles of trifasciatus are here reduced to fine hair and the 

 beard is more abundant and longer in proportion. Palpi and pro- 

 boscis black. Dorsum and pleura? of thorax with fine pile much longer 

 than that of trifasciatus; the presutural and postalar bristles reduced 

 to hair and sometimes absent; scutellum with a fringe of fine long 

 hair. Abdomen immaculate, with fine pile; particularly noticeable 

 on the lateral margins of the segments. Legs wholly white pruinose 

 with fine bristles and silky white pile; claws black; pulvilli sordid 

 white. Wings pure hyaline, with violaceus reflections; fourth pos- 

 terior cell decidedly petiolate at base. All the submarginal and pos- 

 terior cells open; anal cell closed before the margin. 



Type. — Lost. 



Habitat. — Atlantic States; not rare on seabeaches; Avalon, 

 N. J. (July 29, C. W. Johnson); N. J. (Aug. 15 and 27, E. 

 Daecke) ; Lake Frost, 111. (J. G. Needham) ; Los Angeles Co., 

 Cal. (D. W. Coquillett). 



Prof. C. W. Johnson, of whom I have received specimens 

 of this species, says that he has taken specimens in goodly 

 numbers on the sandy stretches of New Jersey. I have also 

 seen it in sandy places at Bedford, Mass. 



Sticliopogon fragilis n. sp. 



9 • — Length about 3 mm. — Head and thorax blackish, everywhere 

 thinly dusted with a grayish bloom, which on the front is more hrown- 

 ish; abdomen and legs sordid pale yellow except the last tarsal segment, 

 which is blackish; wings pure hyaline, in certain light slightly whitish, 

 violescent; all five posterior cells present and wide open; anal cell 

 closed and slightly petiolate; halteres cream-colored. 



In structure like the larger species, but the third antennal segment 

 is a little more swollen at the base. Mystax white, confined to the 

 oral margin; the sparse weak bristles of the occiput white; dorsum 

 of thorax with scant, short white pile and longer white bristles, one 

 on either side before the transverse suture and two upon the posterior 

 callosities; scutellum with a few similar bristles on its posterior mar- 



