NORTH AMEUICAX DIPTERA. 105 



male separated nearly one-third widtli of ocelUir tubercle; thickened basal por- 

 tion of third antennal joint long-conical, the robust styliforni portion scarcely 

 one-half as long as the thickened basal part; face much produced below, pro- 

 boscis projecting half the length of the labellfB beyond the epistonia. Wings 

 hyaline, apical two-thirds of subcostal cell yellow; hind femora with several 

 short bristles, but no long hairs below ; n)iddle femora with one or more bristles, 

 front femora destitute of bristles. Length 7-10 mm. 



Southern California. Five males and five females, in April and 

 May. 



This is the form described in my Monograph (" Can. Ent," I\[ay 

 1886) as Leptochllus modestiis Loew, but it differs from that species 

 in the structure of the antenme, separated eyes of the male, and in 

 having no black scales on the abdomen. 



APHfEKA.XTUS Loew. 



As stated above, Epacraus concinnus, peUuciclus, transitus and fa- 

 mosns belong to Aphoebantus, and I suspect that Epaanun ritfolimba- 

 tus Bigot should also be referred to the same genus. These and the 

 other species known to occur in this country north of Mexico are 

 included in the following table. Aphoebantus rattus O. S., from Texas, 

 belongs to the genus Eucesda. xi. squamosus Coq. is a synonym of 

 A. marcidus Coq. 



1. — Ground color of abdomen black 3. 



Ground color of abdomen yellow, wings hyaline 2. 



2. — Antennse having the two basal joints yellow, scales of abdomen yellow, except 



a cross-band of white scales on second segment coiiciiiiius Coq. 



Antenna; wholly black, scales of abdomen yellow, except those on extreme 



apex of each segment, which are white varius Coq. 



3. — Proboscis never projecting more than the length of its labellae beyond the 



epistoma o. 



Proboscis projecting at least one- half its length 4. 



4. — Face black, proboscis shorter than thorax and abdomen, no brown cloud on 



the small cross-vein litus Coq. 



Face red, proboscis as long as the thorax and abdomen, a brown cloud on 



the small cross-vein riifbliiiibatiiN Higot. 



5. — Thorax destitute of vittse of white scales ti. 



Thorax with two vittse of white scales, front concealed under a dense cov- 

 ering of scales, hind margin of scutellum opaque and scaly. 



vittatus Coq. 



6. — Wings, except sometimes the subcostal cell, hyaline 7. 



Wings brown on basal portion, abdomen destitute of black scales 26. 



7. — Pile of face and front largely or wholly black, knob of halteres light yel- 

 low 8. 



Pile of face white or yellowish ](). 



TKANS. AM. ENT. SOC. XXI. (14) MARCH, 1894. 



