218 DIPTERA OP NORTH AMERICA. [PART IV. 



of the second longitudinal vein, especially the posterior one, 

 arcuated ; second submarginal cell longer than the first posterior, 

 by a distance about equal to the length of the great cross-vein ; 

 second posterior cell short, in comparison to its petiole ; seventh 

 longitudinal vein conspicuously curved at the tip. 



Hab. United States ; common in the vicinity of Washington, 

 D. C, from the earliest spring through the greatest part of the 

 summer. Florida (in March) ; South Carolina ; Massachusetts 

 (Mr. Scudder). 



The forceps of this species is represented on Tab. IY, fig. 25 ; 

 the inner pair of appendages is ciliated. 



I possess a specimen without petiolated (second) posterior cell 

 on both wings. A stump sometimes occurs at the origin of the 

 pragfurca. 



This species, together with L. inornata and contempta, form a 

 separate group, distinguished by the structure of the antenna?, 

 the shape of the head, which is narrowed behind ; the neck-like 

 prolongation of the collare, the venation (length of the second 

 submarginal cell, arcuated course of the posterior branch of the 

 second vein, seventh vein incurved at the tip), etc. All these 

 species have very striking pits or impressions on the humeri, 

 smooth, and as if horny, at the bottom ; in front of the meso- 

 notum, where the intermediate thoracic stripe reaches the collare, 

 there are two small, closely approximated dots with a shining 

 surface. These marks are either black or brown, and somewhat 

 different'in size in the different species. In L. luteipennis they 

 are shining brown and very distinct. Similar pits on the humeri 

 exist in many other species and in different sections (compare the 

 Introduction, p. 29), but they are particularly well marked in the 

 above-mentioned three species, and also in L. fratria. 



14. L,. contempta, n. sp. % and 9 . — Fuscana, thorace concolore, 

 vittis obsoletis, pleuris canescentibus ; alis dilutissime fusco tinctis, 

 unicoloribus ; cellula submarginalis secunda posteriori prima conspicue 

 longior, longitudinalis septirnse apex incurvus. 



Brownish, thorax of the same color, with obsolete stripes, pleurae with a 

 hoary bloom ; wings tinged with pale brown, unicolorous ; second sub- 

 marginal cell considerably longer than the first posterior ; seventh longi- 

 tudinal vein incurved at the tip. Long. corp. 0.21 — 0.25. 



Head grayish-brown, narrowed posteriorly ; rostrum and palpi 



