228 DIPTERA OF NORTH AMERICA. [PART II. 



they exceed the tibiae in length not 'inconsiderably ; the hind tarsi 

 are but a little longer than the tibiae, their firs? joint not much 

 lon<rer than the second. The tibise and tarsi of the hind feet are 



O 



sparsely beset with very short bristles, which, in the female, dis- 

 tinctly differ from the usual short hairs, in the male however 

 scarcely exhibit any difference. The cilia of the whitish tegulae 

 appear in some directions dark-brown, in others shift into yellow- 

 ish. Wings hyaline, little tinged with grayish ; the veins brown- 

 ish ; the long last segment of the fourth longitudinal vein is gently 

 inflected forward and ends rather closely near the end of the third 

 longitudinal vein. 



Hob. Florida. (Osten-Sacken.) 



4. S. tenuis, nov. sp. 9. Dilute fiavescens, fronte, thoracis dorso 

 praeter limbos laterales, scutelloque prseter marginem ex cinereo vires- 

 centibus, pleurarum dimidio superiore et metanoto ex glauco ciuereis, 

 fasciis basalibus segmentorum abdominalium nigris. 



Pale-yellowish, the front, the back of the thorax, with the exception of the 

 lateral margins, and the scutellum with the exception of its margin, 

 gray-greenish ; the upper half of the pleurae and the metathorax green- 

 ish-gray ; abdominal segments at the basis with black bands. Long, 

 corp. 0.13. Long. al. 0.14. 



Pale-yellowish; the face, very narrow for a female, and the 

 palpi have the same color ; both are somewhat covered with whitish 

 dust. Antennnse pale-yellowish, the third joint somewhat infus- 

 cated. The ground-color of the front is greenish, metallic but 

 not shining, covered with rather thick white dust, so that the 

 whole front assumes a pale grayish-green appearance. The 

 greater part of the upper side of the thorax has a similar, but 

 somewhat more green coloring ; however, the humeral region, and 

 in connection with it, a large lateral spot near the transverse 

 suture, the lateral margin above the root of the wing and the 

 posterior corners are of a yellowish color. Scutellum grayish- 

 green with yellowish margin. Almost the whole upper half of 

 the pleura? is greenish-gray, yet the color of the described speci- 

 men is not sufficiently matured for a more precise statement about 

 the extent of this color ; the metathorax is gray. The first ab- 

 dominal segment is blackish at its basis ; the three following 

 segments have each on the anterior margin a broad, black band, 

 which is gradually tapering towards the lateral margin. Feet 



4 



