354 SUPPLEMENT. 



very delicate pale pruinosity, scarcely affecting the metallic reflection. Thorax metallic, bright, on the 

 pleurae in a certain light showing some pure white pollen ; cilia of tegulae dark, halteres pure yellow. 

 Abdomen dark green, the anterior margin of each segment black ; this black band becomes wider on 

 each succeeding segment, until in the last two it is more extensive than the green ; hypopygium black, 

 large and up-curved, with small sordid appendages tipped with black. Pore coxae, except at the tip, 

 green, with white dust and hair, and near the tip with two black bristles ; the other coxae blackish. 

 Femora dark metallic green, with yellow apices. Pore tibiae entirely brownish-black; middle tibiae 

 yellow ; hind ones yellow at the tip, but infuscated on the bas»l half or more. Pore tarsi black ; the first 

 joint long, the third longer than the second, fourth and fifth joints with a dense black fringe on both 

 sides ; middle tarsus with the first joint more than twice as long as the others together, and quite 

 distinctly white at the apex ; the second and third joints equal in length, black, with a black fringe 

 above and below, shorter than in the fore tarsi ; fourth and fifth joints short, black. Hind tarsi entirely 

 brownish-black, rather long. Wings infuscated along the costa from the base to the apex, the basal third 

 or fourth less deeply so, the two cross-bands almost connected in some cases on the fourth vein. 

 Length 7-8 millim. 



Hab. Mexico, Teapa in Tabasco (//. H. Smith). 

 Three males. 



2. Psilopus melampus. 



Psilopus melampus, Loew, Berl. ent. Zeitschr. vi. p. 215 l ; Mon. N. A. Dipt. ii. p. 253*. 



Hab. Noeth America 2 , Las Cruces (Townsend), Santa Fe, New Mexico (Cockerell). 

 — Mexico 1 , Omilteme, Chilpancingo, and Xucumanatlan in Guerrero, Mexico city 

 (//. H. Smith), Jalisco (Schumann), Orizaba (H. II. Smith & F. D. G.), Guanajuato 

 and Orizaba (Townsend). 



Loew suspected, and with reason, that Say meant this species when he referred to 

 P. patibulatus as occurring in Mexico. [See Loew, Mon. N. A. Dipt. ii. p. 256, and 

 Say, Complete Writings, ii. p. 361.] 



P. melampus was included by Osten Sacken amongst the unidentified species of the 

 genus, antea, p. 214. 



3. Psilopus praestans, sp. n. 



<S . Wholly black and green; feet black. Wings with dark cross-bands. Face bright blue, from above with a 

 white reflection, rather narrow, concave in the middle ; antennae small, with a few little hairs on the 

 second joint only, arista short ; front violet, deeply excavated, with very few and minute pale hairs on 

 the sides ; proboscis yellow. Thorax bright metallic green or blue, on the sides thinly dusted, so that, as 

 viewed in some directions, the green is distinct ; halteres rather dark yellow. Abdomen bright green or 

 blue, with narrow black bands on the incisures, the last two segments wholly shining jet-black, with 

 perhaps a trace of violet, the colour markedly contrasting with that of the preceding segments ; bristles 

 moderately stout, depressed; hypopygium small, black, with two conspicuously large black filaments 

 behind. Legs wholly black, the coxae and femora with a slight bluish reflection. Fore tarsi with the 

 first joint equal in length to the tibia, the following joints shortor in succession, the fifth nearly as long 

 as the fourth, a little compressed, and silvered on the inner side (this joint is so small that the ornamen- 

 tation is not striking). Middle and hind tarsi rather stout, especially the third to the fifth joints. Fore 

 coxae with numerous pale hairs and three black bristles. Wings with the usual cross-bands, the interval 



