34 



DIPTERA. 



5. Baccha adspersa. 



Baccha adspersa, Fabr. Syst. Antl. p. 200 l ; Wiedem. Aussereur. zweifl. Ins. ii. p. 97 2 ; Willist. 



Trans. Am. Ent. Soc. xv. p. 269 3 . 

 Bacha adspersa, Schiner, Reise der Novara, Diptera, p. 342 *. 



Eab. Panama, David in Chiriqui (Champion). —Sovtk America 1 2 4 , Brazil 3 . 



A single specimen, agreeing with specimens from Brazil. 



6. Baccha stenogaster. 



Baccha stenogaster, Willist. Trans. Am. Ent. Soc. xv. p. 266 \ 



Eab. Mexico, Rincon in Gnerrero 2800 feet (E. E. Smith).-Somn America, 

 Brazil K 



A single female specimen from Mexico agrees pretty well with a male from Brazil, 

 but it has the face wholly yellow (not chiefly metallic blue), the stigma dark brown 

 (not brownish-yellow), and the hind tarsi brown. The front is shining metallic black, 

 finely rugose. 



7. Baccha rubida, sp. n., «J .<? . (Tab. I. figg. 8, 6 ; 8«, head in profile ; 8 b, 

 head from in front.) 



Aluhe rudimentary ; last section of the fourth vein and the posterior cross-vein sinuous and oblique. Head 

 hemispherical ; front and face small, opaque black, covered with ochraceous pollen and hght-coloured 

 pile • front very narrow above in the female ; face gently convex transversely, nearly straight and gently 

 receding from the antenn* to the oral margin. Antennse yellow, the third joint orbicular. Mesonotum 

 shining red, the anterior part more or less black ; pleurae yellowish-red ; scutellum similar m colour to 

 the mesonotum. Abdomen slender and elongate ; second segment cylindrical, the abdomen gently spatu- 

 late beyond ; reddish-brown, the base of the third and fourth segments yellow. Legs yeUow ; a preapical 

 ring on the hind femora, tho hind tibia3 broadly in the middle, and the hind metatarsi brown ; hiud 

 femora elongate, and gently thickened near the distal end. Wings subhyaliue ; snbcostal cell beyond the 

 auxiliary vein brown ; narrow, but conspicuous, clouds across tbe anterior cross-vein and from the hrst 

 vein to and over the vein at the base of the last posterior cell ; a blackish cloud distally along the 

 costa. 



Length 12-14 millim. 



Eab. Mexico, Omilteme 8000 feet and Sierra de las Aguas Escondidas 9500 feet, 

 both in Guerrero (il. E. Smith). 



Six specimens. 



8. Baccha gracilis, sp. n., 6 $ . 



Face and frontal triangle of the male shining bronze-green, thickly c vered (except along the middle of the 

 triangle) with nearly white dust ; in the female the colour is shming blue, concealed beneath nearly white 

 dust, except a streak along the front and at the vertex. Face gently convex transversely, in profile nearly 

 straight and gently receding from the antennae to the oral margin. Mesonotum shining bronze in the 

 male, blue in the female. Scntellum blue. Abdomen : first segmeut coloured like the scutellum ; second 

 eegment subopaque black, very slender, and of nearly uniform width ; third segment brown or black, with 



