266 ENTOMOLOGICAL NEWS [Nov., '22 



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labium extends rearward only to the middle of the prothorax, its median 

 lobe is broadly rounded and cleft only to the level of the base of the 

 lateral lobes. Each lateral lobe is 3-cleft at the apex into two outer, 



Fig. 2. Mouth parts : a, mandible ; b, end of labium from within ; c, more enlarged tip 



of lateral lobe of labium. 



incurved subacute teeth, and one inner obliquely truncate and scarcely 

 falcate tooth. 



At each side of the pronotum is the usual pair of projecting lateral 

 angles, the rear one being slightly larger; the legs are brown with 

 yellowish tarsi, the femora bare, strongly longitudinally carinate and the 

 tibiae similar, very weakly carinate. Wing tips extend posteriorly to 

 abdominal segment 6. There are high, erect dorsal hooks on segments 

 2 to 9. Gills on 2 to 7 decurved and twisted at the tip, three-jointed, the 

 basal joint bearing very short filaments along one side. There are no 

 lateral spines. 



The lateral gills are wanting. The mid-dorsal gill is of extraordinary 

 form, inflated, heavily chitinized, pedicellate at base and compressed at 

 apex, where it is bifurcated and slightly carinate beneath, where it 

 bears a strong sharp tooth at each end of the inflated portion. There is 

 also a pair of thorn-like processes projecting laterally from the middle 

 of this portion. 



A single 9 specimen from Enafias del Pichis, Peru (east 

 slope of the Andes), July 4, 1920. 



Keys to the Syrphid Genus Sphegina Meigen (Dip.). 



By J. R. MALLOCH, U. S. Biological Survey, Washington, D. C. 

 The genus Sphegina is most closely related to Neoasciit 

 Williston and is separable from it by the conspicuously con- 

 cave face, the sloping instead of erect outer cross-vein, lack 

 of distinct hairs on upper half of sternopleura (except in one 

 or two species, and in these they are very inconspicuous), much 

 shorter third antennal segment, and the presence of a more or 



