262 DIPTERA OF NORTH AMERICA. [PART II. 



taken together ; the second to the fourth joint of gradually de- 

 creasing length, the fifth joint very short. Halteres dingy clayish- 

 yellow, the basis of the peduncle black, and the upper side of the 

 knob brown. Tegulse with a broad black margin and long black 

 cilia. Wings hyaline with black veins ; auxiliary vein unusually 

 indistinct, still present, first longitudinal vein extending far 

 beyond the middle of the anterior margin ; the margin has a fringe 

 of very delicate, erect, curly, minute hairs, from the humeral trans- 

 verse vein to the tip of the first longitudinal vein, which are 

 longest between those two points where the margin is slightly 

 sinuous ; the anterior branch of the fourth longitudinal vein 

 diverges from this at an angle which is almost a right one, and 

 turns afterwards, more in a curve than at an angle, towards the 

 margin of the wing, which it reaches before the apex, immediately 

 near the tip of the third longitudinal vein ; the posterior trans- 

 verse vein is rather oblique and only very little sinuated. , 



Hab. Florida. (Osten-Sacken.) 



Observation. — I have already remarked above, with regard to 

 P. mundus Wied., that P. ciliatus differs from it only by its 

 larger size, its more steel-blue than purplish coloring, and, as 

 it seems, by a very trifling difference in the bristles of the fore 

 tibise ; it is therefore very likely but a mere variety of the former. 



b. First longitudinal vein at the most reaching to the middle of the wing. 

 1. Arista apparently apical and strikingly elon gated. 



9. P. COSSaatllS Loew. % and 9 . — Viridis, ex parte chalybeus, niti- 

 dissirrms, fasciis abdominalibus obscuris nullis, seta antennarum sub- 

 apicali elongata, pedibus longis, gracilibus, dilute flavis, coxis femori- 

 busque nigris, setis in superiore tibiarum anteriorum latere perlongis. 



^ . Setis capitis, thoracis, scutelli abdominisque tenuibus, longissirnis, 

 appendicibus hypopygii pallidis, tarsoruin anticorum articulo prime- 

 tarsisque intermediis superne ciliatis. 



9 . Setis capitis, thoracis, scutelli abdominisque tenuibus, mediocribus, 

 tarsorum anticorum articulo primo setulis minutis subciliato, tarsis 

 intermediis simplicibus. 



Green, partly steel-blue, very shining, without dark bands on the abdomen ; 

 wings without picture ; the elongated arista apparently apical ; feet 

 long, slender, pale-yellowish, coxae and femora black ; the bristles upon 

 the upper side of the four anterior tibiae very long. 



% . Bristles upon head, thorax, scutellum, and abdomen slender, extremely 



