W. G. DIETZ 137 



so, the following four or five joints ovoidal, outer joints cylindrical and atten- 

 uated. 



Thorax entirely yellowish-brown with a few fine scattered hairs. Halteres 

 pale, tip slightly tinged with fuscous. Legs slender, pale yellowish, itars 

 somewhat infuscate, joints darker at tip; the whole leg beset with rather long, 

 blackish hairs, denser and more conspicuous on the tarsi. Wings relatively 

 narrow, tinged with grayish; costal and subcostal cells yellowish; veins fus- 

 cous. Discal cell closed. The seventh vein diverging from the sixth and at- 

 taining the margin of the wing about opposite of middle of vein five. Three 

 fuscous costal spots, one over origin of the praefurca, one midway between the 

 latter and the end of the subcostal vein and one over the last mentioned point ; 

 central cross vein margined with fuscous, likewise the beginning of the two 

 branches of vein two; costal margin beyond apex of subcostal vein to apex of 

 wing infuscate, branches of vein two and vein three, narrowly margined with 

 fuscous. Pubescence sparse, inconspicuous. 



Abdomen fuscous with scattered hairs. Hypopygium yellow; the ninth 

 tergite projects in the form of a subtriangular plate; lobes with an apical, 

 dark fuscous, bird-head like appendage, the latter incurved, hairy. 



Holotype: cf; Hazleton, Pennsylvania. July 11, 1913. 



Type in author's collection. The nearest ally of this species 

 is 0. innocens Osten Sacken, with which it agrees in venation, 

 except that the marginal cross vein in the latter species, is at 

 the point where the second longitudinal vein divides into its 

 two branches, whereas in 0. atriceps this cross vein runs into 

 the anterior branch of vein two. The wing spots in the latter 

 species are very few compared with those of 0. innocens. 0. 

 apicalis differs by its very different wing coloration, being in- 

 fuscated at base and on apical part of wing. 



Ormosia abnormis sp. n. (PL X, fig. 3.) 



Antennae entirely fuscous. Thorax reddish-brown shining. Discal cell 

 closed; the great cross vein about its middle, vein seven diverging from vein 

 six. 



cf, Length, 5 mm.; wing, 4.5 mm. 



Head, palpi and rostrum dark fuscous, the latter shining. Antennae fus- 

 cous, the first two joints stout, clavate, flagellum very slender, outer joints 

 elongate, the whole antennae sparsely beset with long hairs. Eyes contiguous 

 above. 



Thorax reddish-brown, shining; scutel and metathorax subopaque. Hal- 

 teres pale, club infuscate at apex. Legs slender, femora sordid yellowish, 

 fuscous at the tip, tibiae yellowish-fuscous, darker towards the apex, tarsi 

 fuscous. Wings hyaline, pubescence fine and sparse, denser in apical part of 

 wing; stigma concolorous or nearly so; marginal cross vein very faint, discal 

 cell closed, the great cross vein at its middle, veins six and seven diverging 

 towards the wing margin. 



TRANS. AM. ENT. SOC, XLII. 



