204 PROC. E)NT. SOC. WASH., VOL. 21, NO. 9, DEC., 1919 



THE GENERIC STATUS OF ZODION PALPALIS ROBERTSON 

 (DIPTERA, CONOPIDAE), W^TH GENERIC KEY TO THE 



FAMILY. 



J. R. MALLOCH, Urbana, III. 



While visiting Mr. Charles Robertson in 1918 I obtained from 

 him a specimen of his species Zodion palpalis in order to ascertain 

 if it really belonged to the genus in which he had described it, 

 some doubt having been expressed on that point by one of Mr. 

 Robertson's correspondents. The species undoubtedly runs out 

 to Zodion when one uses Williston's key to the genera, but there 

 are some characters which ally it closely with Occemyia as well 

 as those which indicate its affinities with Zodion. In fact, the 

 species possesses some of the characters of both genera and the 

 only course possible to me is to erect for the reception of the 

 species a new genus which is accordingly done in this paper. 



I give a synoptic key to the genera occurring north of Mexico, 

 as the most efficient method of expressing the relations and dis- 

 tinctions of this and other genera. Many of the characters used 

 in the key are used here for the first time. 



Key to Genera. 



1. Pteropleura with a long bristle; vertex, lateral margins of dorsum of 



thorax, and scutellum with a few long strong bristles; anal cell very 



small (Stylogastrinae) Stylogaster Macquart 



Pteropleura unarmed; vertex, lateral margins of drosum of thorax, and 

 scutellum without bristles, or with a few which are but little differen- 

 tiated from the surrounding hairs; anal cell large 2 



2. Third antennal joint with a 3-jointed style at apex; abdomen con- 



stricted basally, the second ?nd usually the third segments longer 

 than broad; subcosta and first branch of radius connected by a 

 cross-vein; halteres with some short hairs at base of knobs on outer 



side (Conopinae) 3 



Third antennal joint with a dorsal arista ; abdomen not noticeably con- 

 stricted basally, the second and third segments each broader than 

 long (Myopinae) .... 4 



3. Propleura with a bristle on lower margin; posterior metathoracic area 



below base of abdomen and extending between hind coxae not uni- 

 formly chitinized, the small portion projecting from between coxae 

 separated from the broad upper portion by a much less heavily chit- 

 inized area; hind femora regu'arly thickened, the thickest part ;il 



middle Conors Liniu 



Propleura bare; posterior metathoracic area below base of abdomen 

 uniformly heavily chitinized; femora irregularly thickened on basal 

 half I'liysuccplniln Sehiner 



