SOUTH AMERICAN DIPTERA. 249 



a female from Brazil, except for the statement appended to his de- 

 scription that the eyes of his male specimen are not contiguous ; in 

 my specimen they are broadly and closely contiguous. There are, 

 however, some other differences from the description. There is not 

 the slightest trace of any yellow hind margin to the 3-6 abdominal 

 segments ; the second segment is wholly pale yellow, except a narrow, 

 equal lateral margin, and a slender median brown stripe, and the 

 first segment is only a little yellow in the middle. Nevertheless, the 

 species must be very closely allied, and, if *S'. concinnits occurs in 

 Brazil, there may be a question as to which of the two is the real 

 tJwraeicus of Macquart. 



1-3. Sargus coarctatus Macquart, Dipt. Exot. i, 1, 263, pi. xxv, tig. 2. — 

 Brazil, Chili. 



Two specimens from Corumbti (May), and Rio Parana, near Bella 

 Vista (Dec), both females, agree fairly well with the description. 

 The wings are only lightly grayish, not brownish. Only the hind 

 legs are black, with the metatarsi (except the narrow tip) white ; a 

 small yellow ring and the narrow base of the tibiae yellow. I can 

 find no other description that will apply well ; S. Sallei Bell., seems 

 the nearest, though the tarsi are different, and, if I understand the 

 description rightly, the species is not a Sargus. However, as regards 

 the related species, compare Osten Sacken, Biol. Centr.-Americana, 

 Diptera, p. 23. 



13. Merosargiis gracilis u. sp. 



5 . — Length 6 mm. Front hroad, with a small median tubercle, and two white 

 spots below ; mesonotum and scutelliim metallic blue; abdomen blackish brown. 

 Front broad, metallic blue, in the middle with a small tubercle ; below, the usual 

 gibbosity well pronounced, the middle of which is brownish, separating two large 

 white spots. Anteniipe brownish or luteous yellow, the third joint lighter; 

 arista black, considerably thickened and hairy at base. Mesonotum and scutel- 

 lum bright metallic blue, with purplish reflections; a slender white line from the 

 humeri to base of wings. Pleurae black, with a yellowish spot below the wings. 

 Abdomen blackish or reddish brown, with purplish reflection?. Front coxae and 

 legs yellow; middle legs yellow with brownish on the outer part of femora and 

 inner part of tibiae ; hind legs blackish brown, the immediate base of femora, 

 the base of the tibiae, and the three basal joints of the tarsi light yellow. Wings 

 only lightly tinged with gray ; second vein as in the following. 



One specimen, Chapada. The species is closely allied, evidently, 

 with M. bituberculatus Schiner, but the difference in the coloration 

 of the thorax and the size (1 3 mm.), will readily separate them. 



TKANS. AMER. ENT. SOC. XV. (32) OCTOBER, 1888. 



