AMERICAN DIPTERA. 309 



Wings longer than abdomen, all the posterior cells broadly 

 open; anal cell variable. 



Type. — Macquart states that D. oculatus, rufitkorax and 

 Discocephala rufiventris (abdominalis) are the typical species. 



SYNOPSIS OF SPECIES. 



Abdomen reddish-yellow abdominalis. 



Abdomen brownish; posterior margins of segments 1-3 grayish prui- 



nose calva. 



Holcocepliala calva. 



Discocephala calva Loew, Cent., X, 35, 1872. 

 Holcocephala calva Osten Sacken, Cat., 1878, 71. 

 (^ 9 • — Length 8-9 mm. — Small black species but with the ground 

 color wholly concealed above by a dark brown bloom and on the face, 

 occiput, humeri, above base of wings, posterior portion of thoracic 

 dorsum, scutellum, pleurae, coxae, metonotum and, in varying degrees, 

 on the posterior margins of the abdominal segments and the venter 

 grayish pruinose. Eyes bronze; antennas and proboscis black; palpi 

 reddish. Mystax, hair of palpi, occiput and legs white. The dark 

 bloom of the thoracic dorsum is broken by indistinct lines of grayish 

 bloom along the sutures. In greased specimens the humeri, posterior 

 callosities and coxse appear reddish. Halteres dark. Abdomen brown- 

 ish pruinose, noticeably contracted toward the base, more slender and 

 elongate than that of abdominalis ; distally, especially in the female, a 

 trifle dilated; penis of male three-pronged, and usually well exerted 

 as in abdominalis. The grayish bands on the posterior margins of the 

 segments appear distinctly only on the first three segments. Legs 

 dark reddish-yellow; all the femora and tibiae darker on their distal 

 portions; the front tarsi darker than the others. Wings blackish, not 

 quite as broad as in abdominalis ; all the posterior cells open, closed 

 or petiolate. 



Type. — M. C. Z. A female specimen. 



Habitat. — Texas (type) ; Western N. Y. (Osten Sacken) ; 

 Princeton (July 21), and Cumberland Co. (Sept. 1); N.J. 

 (Smith Cat.); Phil., Pa. (Aug. 7) ; Tifton, Ga. (Oct. 3, C. W. 

 Johnson) ; Juniper Creek, Fla. (May 15, C. W. Johnson). 



Holcocephala abdominalis (PI. XI, figs., 4, 5; PI. IV, fig. 6). 



Dasypogon abdominalis Say, Jour. Acad. Sci. Phil., Ill, 50, 



1823; Compl. Works, II, 64. 

 Dasypogon abdominalis Wiedemann, Auss. Zw., I, 412, 1828. 

 Discocephala rufiventris Macquart, Dipt. Exot., I, 2, 50, PL IV, 

 fig. 2, 1838. 



TRANS. AM. ENT. SOC, XXXV. AUGUST, 1909 



