C. W. Johnson.
Species of the Genus Gaurax of the Eastern United States.
Psyche 20:34-35, 1913.

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SPECIES OF THE GENUS GAURAX OF THE EASTERN UNITED STATES.
Boston Society of Natural History,
These interesting little flies are only occasionaIly taken in sweeping but can often be obtained in some numbms in breeding other insectsJ as they differ from other members of the family Oscinid~, in feeding upon insect remains instead of vegetable matter. They are not parasitic but inquilinous or more properly speaking scavengers, the larvz feeding upon the cast-off skins of caterpillars, pup cases and spider eggs. Gaurax anchora Loew has been bred from the cocoonsJ etc.? of Samia cecropiay Hemerocampa leucostigma (Tussock moth); Porthetria dispar (Gypsy moth), and egg cluster of Coydalis cornutus. Gaurax araneE Coq., of California was reared from the egg-sac of a spider (Argiope riparia), and Gaurax lancifer Coq. of the West Indies, also from egg-sacs of spiders. The habits of the other species are unknown. The Gaurax ephippium Zett. re- ferred doubtfully to this genus by Coquillett in the list of Diptera of Beulah, New Mexico, (Trans. Amer. Ent. Soc., XXIX, 106? 1903) is a Chlorops according to European authors. In studying the New England species collected during the past few years, I find one new species, making four from this region. They may be tabulated as follows:-
............................... 1 Thorax ello ow, with a black dorsal mark. .2 Thorax entirely black; scutellum yellow. ..................... montanus Coq. .............................................. 2 Wings entirely hyaline. .3 Wings with the basal half smoky black. ................ .obscuripennis sp, n. 3 Thorax with a narrow anchor-shaped mark; scutellum also marked with black. ................................................. anehora Loew Thorax with a broad mark, the posterior edge tridcntate; scutellum entirely yellow. .................................................. festita Loew Gaurax monhus Coquillett ,
Aside from the type locality, White Mountains, N. H,, I have collected this species at Norwich, Vt., July 8, 1908.



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1913)
Johnson-Species of the Genu8 Gaurax of the Eastern United States 35
Gaurax obscuripennis sp. nov.
Face blacky front brown* vertex yellowy ocellar triangle and occiput black; basal joints of the antenne. yellowishy third joint black, ark& whitish* densely pilose. Thorax yellowy with whitish hairs and a dorsa lline* broad in front and be- coming gradually narrower posteriorly, humerusy a small spot in front of the wing, and a large spot on the center of the pleuray black* the metanotum yellow, with a black spool-shaped mark. Abdomen black. Halteres black* stems light yellow. Legs light yellowy the apical third of the posterior femora black. Wings smoky,
the basal half forward of the fifth longitudinal vein blackish. Length, 1.5 mm.
One specimen, Chester, Mass., August 7, 1912. Type in the
collection of the Boston Society of Natural History. Gaurax anchora Loew.
Elachiptera &spar Willistony in Furbush and l?ernaldy Rept. on Gypsy Moth, 1896y p. 39OY pl. 53å fig. 12.
Collected by the writer at Weston, Mass., July 23, 1911. Gaurax festivus Loen.
Beverly, Mass., July 20, [Burgess] (U. S. Nat. Mus.) ; Auburn- dale, Mass., June 12; Pottstown, Pa., August 8, (C. W. Johnson). In addition to the above the following species was discovered among some unidentified material.
Gaurax pseudostigma sp. nov.
9 Facey front and antenne. yellowy ocelli and occiput black. Thorax and scutellum yellowy with whitish hairsy metathorax shining, yellow, with a narrow band of black below the scutellum. Abdomen yellowy with broad bands of black on the posterioi portion of the segmentsy the first narrowly interrupted. Halteres and legs light yellow. Wings hyaline, with a black stigma-like spot at the end of the marginal cells. Lengthy 1.5 mm.
One specimen, Toronto, Ontario, Canada, July 4, 1911 (M. C. Van Duzee).




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