CHRYSOTUS. 181 



S. C. suI>costatus ? nov. sp. % . — Viridis, polline raro ex fusco pine- 

 reo aspersus, femoribus nigris, viridi-micautibus, genibus tibiisque 

 flavis, maris oculis distantibus et media parte costse modice incrassata. 



Green, sparsely covered with brownish-gray dust ; femora black, with 

 green lustre ; knees and tibiae yellow ; the eyes in the male separated, 

 and the costa moderately thickened. Long. corp. -0.09. Long. al. 0.09. 



Metallic-green or blue-green, upon the thorax with not very 

 thick brownish-gray dust and therefore less shining. Face for a 

 male rather broad, towards the bottom somewhat narrower, with 

 very thick brownish-gray dust. Palpi near the root and margin 

 blackish, upon the middle more brownish ; it was not possible to 

 distinguish their color with certainty in the described specimens. 

 Third joint of the antennae very small ; arista apical ; front quite 

 opaque on account of a covering of brownish-gray dust. The 

 scutellum and especially the abdomen have very little dust and 

 are shining. The hair upon the abdomen is black. Coxa? and 

 femora black, the latter with a very bright green metallic lustre ; 

 the second joint of the fore coxa?, the tip of all femora, the tibiue 

 and all the tarsi as far as the end of the first joint, yellow ; the 

 tip of the tarsi dark brown. The hairs and bristles upon the feet 

 everywhere very short, the bristles at the same time very scarce. 

 Pulvilli of the fore tarsi rather small. Cilia of the tegulaa whitish. 

 Wings grayish with a rather protruding anal angle ; the anterior 

 margin of the wings shows a not very strong, but distinctly visible 

 thickening, which begins abruptly at the end of the first longitu- 

 dinal vein and thence gradually decreases towards the tip of the 

 wing ; the last segment of the fourth longitudinal vein is scarcely 

 a little inflected, parallel with the third, and ends a little before 

 the extreme tip of the wing ; posterior transverse vein rather 

 equidistant from the root and the tip of the wing. 



Hab. Illinois. (Le Baron.) 



Observation. — G. subcostatus is easily distinguished from the 

 male of G. costalis by the smaller antennae, the less thickened 

 costa, the thinner cover of dust, and the green metallic lustre of 

 the femora ; from all other species it is distinguished by the 

 thickening of the costa. 



