GYMNOPTERNUS. 89 



other females. Whether they 'are, as I suppose, merely a variety 

 of G. frequens, or whether they belong to another closely re- 

 lated species can only be determined by further observations. 

 The changes in size of the present species are not so striking as 

 would appear from the measurements given above, because the 

 larger specimens are always females, which, in this species, more 

 than usual exceed the males in size. It will be quite difficult to 

 distinguish the female of G. lunifer from that of G. frequens. 



12. G. lunifer LOEW. . Obscure viridis vel aeneo-viridis, anten- 

 nis nigris, facie et fronte cinereis, pedibus flavis, lamellis hypopygii 

 obscure luteis. 



Dark-green or bronze-green, antennae black, face and front gray ; feet yel- 

 low; lamellae of the hypopygium dark-yellow. Long. corp. 0.13 0.14. 

 Long. al. 0.13 0.14. 



SYN. tiymnopternus lunifer LOEW, Neue Beitr. VIII, 32, 11. 



Dark-green, rather bright, face and front with whitish-gray 

 dust. Antennae rather short, entirely black, the third joint small, 

 not rounded at the end. Arista with a short but distinct pubes- 

 cence. Cilia of the inferior orbit black. Upon the scutellum, 

 besides the bristles, a few not easily perceptible hairs ; the lamellae 

 of the hypopygium a little larger than those of the kindred species, 

 crescent-shaped, but rounded on the upper end, so as to become 

 somewhat kidney-shaped, and thus to approach the shape of the 

 lamellae of G. subdilatatus. They are of a dingy brownish-yellow 

 color, and upon the upper margin somewhat blackish. Their 

 black fringe is not so strong as that of G. subdilatatus. Fore 

 coxse dark yellow, a little brownish at the extreme basis ; the mid- 

 dle and hind coxas black almost up to the extreme tip. Feet 

 somewhat dark yellow, rather slender, hind femora somewhat iu- 

 fuscated on the upper side towards the tip. The usual row of 

 bristles on the upper side of the fore tibiae is complete. Tarsi 

 brownish towards the tip. Cilia of the tegulse black ; wings tinged 

 with brownish-gray. 



Hob. New York. (Osten-Sacken.) 



13. G. fimbriatus LOEW. $ . Viridis, pedibus et coxia flavis, coxis 

 intermediis, apice excepto, nigricantibus ; appendicibus hypopygii inte- 

 rioribus elongatis et penioillatis. 



