1893.] MR. E. E. AUSTEX OX X'EW DlPTEliOUS IKSECTS. 147 



concave posteriorly, ou the hinder half of the segment, widely 

 separated, however, from tlie posterior margin ; in front of the 

 black band is a small elongate and somewhat oblique yellow mark 

 on each side, between which a uarro^^■ median dead-black stripe runs 

 forwards from the cross-band, and bifurcates anteriorly ; third 

 segment similar to the second, except tlmt the lateral yellow 

 dots are more quadrate and less oblique, and that the median dead- 

 black stripe does not bifurcate in front, but has a club-shaped 

 head, which touches or is narrowly separated from the an- 

 terior margin of the segment ; the fourth segment is shorter 

 and broader than the third, but is similar to it, except that the 

 yellow marks, whicli are duller and not so sharply defined, and 

 sometimes indistinct, are considerably larger and elongated longi- 

 tudinally ; fifth segment \^•holly metallic black ; genitalia metallic 

 bluish blaclv, small. The abdomen is sparsely clothed with very 

 short black pile. Legs : anterior pair brown, darkest on the tarsi, 

 which are flattened ; the femora at the extreme base and at the 

 tip, the tibise at the base and at the extreme ti]:», yellow ; the 

 femora are also yellowish in the iniddle on the inside ; second and 

 third pairs of legs blackish brown, the tips of the femora, bases of 

 \ he tibia?, and extreme tips of the middle tibiae, yellow : the middle 

 femora have a fringe of dark hairs, the posterior coxa? a fringe of 

 pale yellow hairs beneath. Wings uniformly pale brown, except 

 the subcostal cell, which is dark brow^n. lialteres orange. 



Brazil, region of the Amazon {Bates) : three males. 



This species is allied to Bacclui hrev'ij)cnms and B. nigosifrons of 

 tSchiner (Reise 'Novara': Diptera, 341) and to B. slenogaster, 

 AVilliston (Trans. Amer. Ent. 8oc. xv. 260) ; it is, however, distin- 

 gidshed at once fi om the t\\ o first mentioned by the yello^^" spots on 

 the abdomen and by the infuscated wings, as well as by its dark 

 legs in the case of rugosifrons, and irom steiiogaster by its infuscated 

 wings and dark legs. 



Baccha bigoti, nom. nov. 



8yn. Bacclia apicaUs, Bigot (nee Loew). Bigot'is species was 

 described from Brazil (Ann. 8oc. Ent. Fr. G sor., t. iii. p. 334, 

 lb83) ; Loew's from Japan (Wien. ent. Monatschr. Bd. 2, 

 p. lOG, 1858). 



The rdulce are about half the normal size, with a straight pos- 

 terior edge. 



Baccha incompta, sp. u. (Plate IV. fig. 13, J .) 



(S . Length ](> mm. 



Metallic darl' Jirown, neiirhj hare : trliigs hgaliiie, the costal 

 and subcostal cells, a somewhat zigzag mark from the first to the 

 fifth longitudinal vehis, crossing the origin of the third vein and 

 involving the cross-veins at the tip of the posterior basal cell, and a 

 blotch at the tip of the submarginal cell, slightly overfioiving into 

 the margined, brown ; alalce of the full size. 



Face and cheehs metallic steely blue ; tlie former without u 



10* 



