SYNOPSIS OF NORTH AMERICAN SYRPHID^. 117 



•7. —Wings subcinerescent ; all the veins, except the last segment of the fonrth, 



broadiy clouded with blackish, confluent near the costa .... lugens 



Wings with a triangular hyaline space behind the outer end of third vein, tlie 



axillary portion more or less subhyaline fuscipennis 



8.— Wings wholly blackish latiuscula 



Wings broadly hyaline from before the tip of first vein to tip of sixth vein, basal 



part black dimidiata 



Wings nearly hyaline, the immediate base, the costal and subcostal colls and a 

 broad triangular cross-band reaching to the outer part of the sixth vein, 

 dark brown torva 



For other species, see descriptions. 



Baccha Tarchetius. 



Bacclia Tarchetius Walker, List., etc., iii, 549. 



Habitat. — Kew Jersey ! . 



$ . Length, 10.5"^™. Distance from ocelli to base of antennae consid- 

 erably greater than thence to oral margin. Frontal triangle black, a 

 little shining, with black pile; large, with a large semicircular grooved 

 space above the base of the antennte; narrowly whitish pollinose on the 

 sides below, like it is on the face. Basal joints of antennae yellowish, 

 third joint short oval, brown ; arista black. Face yellow, thinly whit- 

 ish pollinose on the sides, in the middle with a broad shining black 

 stripe, narrowed below the tubercle. Posterior orbits narrowly whitish 

 pollinose. Thorax shining greenish-black, with whitish pile; on the 

 pleurae a small vertical yellowish spot. Abdomen moderately slender, 

 opaque black; the first segment, the second segment narrowly in front, 

 along the sides and a posterior band, shining metallic green; third seg- 

 ment narrowly in front, a posterior band a little dilated in the middle, 

 and along the sides, more broadly in front, narrowly behind, the same 

 metallic green, on the lateral shining places near the front a small yel- 

 low spot; fourth segment similar, the yellow spots larger and the pos- 

 terior band more dilated in the middle; remainder of the abdomen 

 wholly shining; the second segment is cylindrical, the third much 

 broader behind. Legs yellow ; hind femora with a broad ring before 

 the tip, the hind tibiae, except the base, and the hind metatarsi, blackish. 

 Wings hyaline, with a broad dark-brown anterior border filling out the 

 first posterior cell to a little beyond the cross-vein, thence following, 

 but not exceeding, the third vein to the tip; a small hyaline spot in the 

 marginal cell near the origin of the third vein. 



One specimen, from Mr. Keen. 



Baccha Babista. (Plate IV, fig. 9.) 



Bacclia Bahista Walker, List, etc., iii, 549 {$). 



Spazigaster hacchoides Bigot, Annales Soc. Ent, de France, 1883, 326. 



Habitat. — Georgia, Florida, Arizona, California ! 

 9 . Length, 10 to ll""". Face considerably projecting below, gently 

 concave below the antennae, tubercle large, obtuse, not receding below; 

 light yellow, the cheeks, and a narrow line along the oral margin to 



