XXII BUIJ.ETIX 31, UNITED STATES NATIONAL MUSEUM. 



BRACHYOPIXI. 



Moficaw sizefl, nearly bare species, chiefly or tchoUy reddish or luieouSy 

 or, if ill hirtjc part blacl, without light yellow markings. Antennae short; 

 abdomen not clnhshaped; anterior cross-vein before middle of the discal 

 cell, iniirginal cell icidc open. 



a. Kpislom.i inodiHi'd into a long Klender porrected snout; femora sleiidcr; the 



third longi'ndinal vein joins the costa beyond the tip. ..EiiiXGiA Seopoli. 

 aa. I'ii'O not so produced, bind temora more or less tbickened. 



b. Face produced, ol)tusely tuberculate, thorax with bristles, abdomen elongate, 



EUGEXIAMYIA Will. 

 bb. Face carinate, abdomen oval, first posterior cell short petiolate. 



c. Arista bare Bkachyopa Meig. 



cc. Arista i)luuose Exochila Rond. 



These genera present a considerable divergence, but are best asso- 

 ciated togetlier. Why they shouUl hitherto have been classed among 

 the VoluceUinw, rather than the Syrphinw, I do not understand. Bhingia 

 is well marked in its remarkably projecting epistoma. In neuration it 

 finds its greatest resemblance in some species of Chilosia. 



lirachyopa, Exochila, and Eugeniamyia are all closely allied, and might, 

 perhaps, be best associated in the same genus. There is a tendency in 

 all the genera to the presence of thoracic bristles. 



VOLUCET^LINI. 



Mostly large species, uniform in color or variable. Third joint of the 

 antenna' more or less elongate, the arista always plumose ; eyes usually pilose ; 

 body nearly bare or thickly pilose ; abdomen short, thick, strongly convex^ 

 above; marginal cell (f the wings usually closed and petiolate, third longi- 

 tudinal vein nearhj straight, the fourth vein joins the third a considerable 

 distance before the tip, inflected; anterior cross-vein usually toicards the 

 base of discal cell; legs slender, hind femora never thickened. 



a. Arista very densely plumose, appearing like a solid mass. ..("opestylum Maeq. 

 aa. Arista featlirry i)luuios(', Volucp;lla Geof. 



The ])reseiit and following groups contain, with few exceptions, more 

 robust, thick-set, and usually pilose, species. The two genera from the 

 United States, located here, are sharply separated from all others by 

 the presence of a closed marginal cell and plumose arista. In certain 

 species of Volucella, however, the marginal cell is closed very near the 

 tip of the second longitudinal vein, and rarely, in some individuals, is 

 narrowly open. Such si)ecies form the natural connection wit!i Fhala- 

 cromyia, difleringouly in this respect, a genus, so far, extralimital, and 

 bearing the same relation to Volucella that Ilelophilus does to Eristalis. 

 It is very desirable that Volucella should be divided ; the species are 

 numerous, and a considerable variation exists among them. No char- 

 acters have, however, in my opinion, been lound that will accomplish 

 this result satisfactorily. Temnocera St. Farg. & Serville, and Atem- 

 nocera Bigot, are too artificial in their limitations. The former is based 

 upon the excision of the third joint of the antennje and the presence of 

 bristles upon the scutellum. In a number of species the bristles are 



