SOUTH AMERICAN DIPTERA. 245 



tibiae straighter and less dilated, etc. The species are evidently all 

 closely allied, and confusion in their discrimination will prevail till 

 some better characters are applied than have been hitherto. 



2. Beris bellula u. sp. 



% . — Length 7 mm. Mesouotum bronze black, scutellum green; antennse 

 short; wings blackish. Antennfe black, third joint red at the base, a little 

 longer than the first two joints together. Face and frontal triangle silvery prui- 

 nose, the latter just above base of antennae blackish. Proboscis yellow, tip of 

 palpi black. Eyes thinly pilose. Mesonotum dark bronze, with dark fulvous, 

 anteriorly blackish, pile. Scutellum bright shining metallic green, with six 

 strong, nearly equal black spines. Pleurae shining black, with white pile. Ab- 

 domen brownish black, along the middle broadly luteous (perhaps variable) ; 

 venter mostly yellow. Legs yellow ; a ring near the tip of the four front femora 

 and tlie distal four tarsal joints of the same pairs, brownish ; tip of hind femora 

 broadly and the distal four joints of hind tarsi blackish. Wings blackish, the 

 stigma but little darker. 



One specimen, Rio de Janeiro, August. Resembles B. mexicana 

 Bell., but differs in color of face, thorax, wings, legs, etc., and in the 

 non-dilated hind metatarsi. 



3. Beris pulchella n. sp. 



% . — Length 6 mm. Mesonotum and scutellum bright shining green ; antenna 

 elongate; wings blackish. Antennae as long as the head, yellow or brownish < 

 yellow, the third joint blackish toward the tij). Face and front silvery pruinose, 

 a blackish spot above the base of the antennae Tip of palpi black. Eyes thinly 

 pilose. Mesonotum and scutellum bright metallic green, the former often with 

 blue or violet reflections, pile fulvous, blackish in front. Pleurae shining, greenish 

 black, with white pile. Scutellum with six moderately strong black spines. Ab- 

 domen yellowish red in front and along the sides, the terminal segments black, 

 on the middle of the disc brownish. Coxae and femora reddish yellow ; tibiae 

 wholly, front tarsi, tip of four posterior metatarsi, and the remaining joints 

 black, the four posterior metatarsi otherwise nearly white. Wings blackish or 

 brownish ; the stigma only a little darker. 



9 . — Front steel-blue. Abdomen brown or blackish throughout. Legs yellow, 

 a small brownish ring on distal part of hind femora, and the distal half of hind 

 tibiae and all the tarsi except the metatarsi, black or brown. 



Four males and one female, Chapada, November. The female 

 specimen is not in good preservation. 



4. Heriuetia illucens Linne, Wiedemann, etc. [For the synonymy see 



Osten Sack en or Lynch, Catalogues]. 



Six specimens from Rio de Janeiro agree well in color and size 

 with North American ones. As in those, only the hind tibise are 

 yellow at the base. I would call attention to a sexual difference in 

 the antennae, which seems to occur frequently in this genus, namely, 



