LIMNOBIA. 95 



yellowish, immaculate, with four small brown clouds along the anterior 

 margin ; the marginal cross-vein at some distance from the tip of the 

 first longitudinal vein. Long. corp. 0.4. — 0.45. 



Stn. Limnobia tristigma 0. Sacken, Proc. Entom. Soc. Phil. 1859, p. 216. 



Head, rostrum, and palpi black, front slightly hoary ; the first 

 antennal joint black at the root, yellow towards the tip ; the fol- 

 lowing four or five joints pale yellow; the remainder of the joints 

 infuscated at the basis. Thorax pale ferruginous ; a broad brown 

 stripe extends over the collare and the anterior part of the meso- 

 notum ; halteres yellow, slightly brownish at the tip ; feet yellow- 

 ish-tawny ; femora with two brown bands, one beyond the middle, 

 the other near the tip. Abdomen yellow. Wings yellowish ; 

 stigma pale, infuscated at both ends ; a small rounded cloud at 

 the tip of the auxiliary vein ; another one, but much paler, at the 

 origin of the praefurca ; the stigmatical cross-vein is in the middle 

 of the stigma, at some distance from the tip of the first longi- 

 tudinal vein. 



Hab. Near Chicago, 111., in July, 1859, five male and six female 

 specimens. 



This species is somewhat 'like the European L. tripunctata 

 Fab. ; only in the latter the marginal cross-vein is infuscated, 

 and not the two ends of the stigma ; the three clouds are also 

 much darker than in L. tristigma. 



9. L,. sociabilis, n. sp. 9 • — Ochracea, fronte et abdomine superne 

 infuscatis ; thorace vitta fusca ; alis immaculatis ; venula marginali 

 transversa ab apice venae longitudinalis modice remota. 



Ochraceous, front and the abdomen above, infuscated ; thorax with a brown 

 stripe ; wings immaculate ; the marginal cross- vein is at a moderate 

 distance from the tip of the first longitudinal vein. Long. corp. 0.35. 



Head yellow ; rostrum and palpi likewise ; front and a part 

 of the vertex infuscated ; antennae yellow. Thorax ochraceous- 

 yellow, shining above, with a broad brown stripe extending over 

 the collare and the middle of the mesonotum ; vestiges of lateral 

 stripes, coalescing with the intermediate one ; scutellum and meta- 

 thorax brownish in the middle. Halteres brownish-ochraceous, 

 paler at the base. Abdomen brownish above, j^ellow on the under 

 side ; ovipositor with remarkably straight upper valves. Wings 

 yellowish, immaculate ; the marginal cross-vein is a little beyond 



