1893.] MR. E. E. AUSTEN ON NEW JJIPTEEOUS INSECTS. 1-17 



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

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

 black baud is a small elongate and somewhat oblique yellow mark 

 on each side, between which a narrow median dead-black stripe runs 

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

 segment similar to the second, except that the lateral j'ellow 

 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, which are duller and not so sharply defiued, and 

 sometimes indistinct, are considerably larger and elongated longi- 

 tudinally ; fifth segment wholly metallic black ; genitalia metallic 

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

 short black pile. Leijs : anterior pair brown, darkest ou the tarsi, 

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

 tip, the tibise at the base and at the extreme tip, yellow ; the 

 femora are also yellowish in the middle on tlie inside ; second and 

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

 the tibiae, and extreme tips of the middle tibife, yellow : the middle 

 femora have a fringe of dark hairs, the posterior coxae a fringe of 

 pale yellow hairs beneath. Wings uniformly pale brown, except 

 the subcostal cell, which is dark brown. Halteres orange. 



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



This species is allied to Baccha hrevipetinis and B, rur/osifroiis of 

 Schiner (Reise 'Novara': Diptera, 341) and to B, stemgaster^ 

 AVilliston (Trans. Amer. Ent. Soc. xv. 266) ; it is, however, distin- 

 guished at once from the two first mentioned by the yellow spots on 

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

 legs in the case of rugosifrons, and ivomste nog aster by its infuscated 

 wings and dark legs. 



Baccha eigoti, nom. uov. 



Syn. Baccha ajncalis, Bigot (nee Loew). Bigot's species was 

 described from Brazil (Ann. 8oc. Ent, Fr. 6 ser., t. iii. p. 334, 

 1883) ; Loew's from Japan (Wien. ent. Monatschr. Bd. 2, 

 p. 106, 1858). 



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

 terior edge. 



Baccha incompta, sp. n. (Plate TV. fig. 13, J .) 



c? . Length 10 mm. 



Metallic darJc hrown, ncarhj hare : icings 7n/aUne, ilie costal 

 and subcostal cells, a souieiuliat zigzag marJc from the first to the 

 fifth longitudinal veins, crossing the origin of tlie third vein and 

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

 blotch at the tip of the sidnnarginal cell, slightly overflowing into 

 the marginal^ brown ; alulce of the full size. 



Face and c?ieel:s metallic steely blue ; the former without a 



10* 



