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 first joint not much 

 longer than the second. The tibiae and tarsi of the hind feet are 

 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 tegulaa 

 appear in some directions dark-brown, in others shift into j r ellow- 

 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. 



Hab. Florida. (Osten-Sacken.) 



4. S. tenuis, nov. sp. 9 • — Dilute flavescens, fronte, thoracis dorso 

 prseter limbos laterales scutelloque prseter marginem ex cinereo vires- 

 centibus, pleurarum dimidio superiore et metanoto ex glauco cinereis, 

 fasciis basalibus segmeatorum abdoniinaliuni 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 pleurse 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. Antennnae 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 pleurae 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 



