90 DIPTERA OF NORTH AMERICA. [PART IV. 



the tip of the auxiliary vein, usually has the posterior brauch 

 (ending in the first longitudinal vein) distinctly longer than the 

 anterior one (ending in the costa). 



3. L.. solitaria 0. S. % and $.— -Thorax vitta media pallida, fusco 

 marginata ; halterum capitulo infuscato ; alse fusco-maculatse et nebu- 

 losae, in cellula basali prima serie punctorum fuscorum ; venula trans- 

 versalis marginalis juxta apicem venae longitudinalis primse sita. 



Thorax with a pale intermediate stripe, margined with brown ; knob of the 

 halteres infuscated ; wings spotted and clouded with brown ; a series of 

 brown dots in the first basal cell ; the marginal cross-vein at the tip 

 of the first longitudinal vein. Long. corp. 0.4 — 0.5. 



Syn. Limnobia solitaria 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 215. 



Rostrum and palpi infuscated ; front with a yellowish cinereous 

 reflection ; vertex infuscated, with a yellow line in the middle ; 

 antennas brown ; first joint yellow ; the two or three following 

 yellowish at the basis, infuscated at the tip. Thorax yellow ; in 

 the middle a pale yellowish stripe margined with brown ; these 

 brown margins are more or less broad, so as to invade sometimes 

 nearly the whole stripe, except a yellowish line in the middle ; 

 two lateral brown stripes, extended beyond the suture behind ; 

 scutellum and metathorax pale yellowish, sericeous, both with 

 lateral brown spots ; halteres with brown knobs ; femora with a 

 brown band at the tip, preceded by a pale one ; tibiae and tarsi 

 yellowish tawny, the former infuscated at the tip, the latter 

 beyond the tip of the first joint. Abdomen yellowish-ferruginous ; 

 an indistinct brown band, formed by a series of spots, in the 

 middle of the back ; genitals pale ; male forceps like Tab. Ill, 

 fig. 6 ; the ovipositor has the horny transverse piece, to which 

 the upper valves are fastened, very broad and stout ; this causes 

 the basal portion of the valves to appear more divergent. Wings 

 yellowish, with brown spots and clouds ; an oblique spot extends 

 from the inner end of the stigma to the inner end of the sub- 

 marginal cell ; the posterior end of the stigma is likewise infus- 

 cated ; a series of brown dots begins with one at the inner corner 

 of the first basal cell and extends more or less far along the middle 

 of this cell ; they are more or less numerous ; sometimes eight or 

 nine, reaching the inner end of the submarginal cell, sometimes 

 only two or three at the inner end of the basal cell ; the spot 

 nearest to the cloud at the origin of the praefurca is often the 



