SOUTH AMERICAN DIPTERA. 267 



of the abdomen. In one of the specimens, the hind tibite and tarsi 

 are a little darker colored, and the fourth abdominal segment does 

 not show a yellow baud at its base. 



28. Baccha variegata Macq. 



A male specimen from Rio de Janeiro. Macquart's description 

 leaves no doubt of the determination. The third vein is less convex 

 and the fourth less oblique than he figures them. 



29. Bacclia exigna u. sp. 



'^ 5 " — Leujitli 5 V mm. Face ami front yellow (or reddish yellow), uarrow ; a 

 small round black spot near the base of the antennae above ; from just in front 

 of the ocelli, whicli are rather remote from the vertex, the front is shining 

 black. Antennse reddish yellow, small. Mesonotum, except a yellow lateral 

 stripe, shininw black, with three densely pollinose, approximate, light yellow 

 stripes, the median one reaching nearly to the scutellnm, the lateral ones abbre- 

 viated behind. Scutellum yellow, a large semi oval spot on the dorsum, and a 

 small one on each lateral margin at the base, deep shining black. Pleurse yellow, 

 with two or three metallic blue spots; pectus metallic blue. Abdomen elongate 

 spatulate in the female, narrower and more cylindrical in the male : shorter than 

 the wings; shining black, in the female with three longitudinal yellow stripes 

 on each of the segments and an oblique lateral spot (effected by drying?). Legs 

 yellow ; hind femora before the end with a blackish, hind tibiae with two narrow 

 brown rings. Wings hyaline ; subcostal cell brown ; a triangular brown spot 

 filling out the end of the submarginal cell from beyond the end of the fourth 

 vein ; third vein nearly straight, terminating at the tip of the wing; last section 

 of the fourth vein nearly straight and rectangular; alulse rudimentary. 



Two specimens, Chapada. 



.30. Bacclia eoujiincta Wiedemann (Syrphus). 



Wiedemann's description applies excellently to a single female 

 specimen, except in the color of the terminal segments of the abdo- 

 men ; the third and fourth segments are black with a yellow anterior 

 band, the fourth and fifth with two yellow longitudinal spots. The 

 elongate antennte and the unusual shape of the abdomen, which ac- 

 quires its greatest width in the third segment, make the insect rather 

 peculiar for a Baecha ; nevertheless, its relationship with B. phceop- 

 tera is very evident. The anterior tarsi are dilated in the female, 

 and the ocelli are placed considerably forward. 



31. Bacclia pliaeoptera Schiner. 



Numerous specimens, Chapada. In the second line of Schiner's 

 description diverglrend should be read for " convergirend." In all 

 the specimens, there is a median linear yellow stripe. One of the 

 specimens with the rest I am in doubt whether to locate with this or 



