114 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



broader than long. Coxa3 and legs white ; a broad preapical ring on 

 the hind femora, hind metatarsi, and the last two joints of all the tarsi, 

 black ; two small, incomplete rings on the hind tibiae, blackish. Wings 

 hyaline. 



^ . Thorax blackish above, sometimes wholly black except the humeri 

 and below them. Abdomen of moderate length, sometimes nearly black, 

 except the basal part of the third segment, the fourth segment always 

 more brown than in the iemale ; front and middle tibite sometimes faintly 

 brownish near their middle. 



This species differs from lohata, to which it is most nearly allied, be- 

 sides the coloration, in the anterior distal angle of the first posterior 

 coir being more acute, and the abdomen of the male being very much 

 less slender. Four female and three male specimens, captured by Mr. 

 Eugene L. Keen, in Fairmount Park, Philadelphia, May 21. The 

 black markings, in both male and female, vary much in intensity on the 

 abdomen. 



Sphegina mfiiscata. (Plato IV ; tig. 12.) 



Splicgliia tnfuscata Loew, Ceutur., iii, 23. 



Hahitat. — Sitka (Loew), Oregon! 



5,9. Length, 5 to 0^™'^, of wings 6^ to G^™"". Head black, opaque ; 

 front of male narrower than that of female, and clothed with longer, 

 black ])ile. Antennse black. Thorax fuscous black ; the dorsum with 

 delicate pile, longer and more obscure in the male than in the female. 

 Scutellum and metanotum of the same color as the thorax. Abdomen 

 shorter than in the species indigenous to Europe, and attenuate near 

 the base, in tlie male fuscous, iu the female reddish testaceous. Legs 

 of the male fuscous, of the female reddish testaceous. Wings large, 

 dilutely infuscate; stigma elongate, fuscous, apical angle of first poste- 

 1 ior cell acute. — Translation from Loew, compared with the types. 



A single specimen from Mount Hood, Oregon, probably belongs to 

 this species, most especially characterized by the short abdomen, the 

 large wings, and acute posterior cell. The specimen, a female, however, 

 has the abdomen and legs wholly light-yellow, and thorax more brown 

 than black; it may be teneral. 



Sphegina rufiventris. 



Sphegina rufiventris Loew, Ceutur., iii, 22. 



Habitat.— ^Gw York (Lw.), Washington Territory! 



9 . Length, 0.^""»^. A very variable species. Eed. Dorsum of thorax, 

 except the humeri aiul posterior angles, always black, sometimes the 

 thorax almost wholly black. Front black, of equal width. Face yel- 

 lowish, above somewhat blackish. Occiput black. Third joint of the 

 antennae fuscous or black. Scutellum sometimes red, often piceous, 

 rarely black. Abdomen red, shining; base often black, distal half less 

 broad than in 8. lohata. Front and middle legs yellowish, last two joints 



