DIPTERA. 357 



base only a little paler, the last three joints of about equal length, glabrous, flattened. Wings subhyaline, 

 with the usual cross-bands, which are connected on the fourth vein in all the specimens before me. 

 Length 4-2-5 millim. 



Hab. Mexico, Cuernavaca in Morelos, Teapa in Tabasco (H. H. Smith).— Brazil, Rio 

 Janeiro. 



Five males from Mexico and a male from Brazil, the latter given me by Prof. Williston. 



9. Psilopus atricauda, sp. n. 



<? . Face blue, very thinly dusted, narrow on the lower half and in a certain light more distinctly pollinose ; 

 antenna small, black, the extreme base below yellow and arising from a yellow area that is slightly visible 

 below them, the second joint with only very few and short hairs ; front deeply excavated, blue or violet, 

 with a few small hairs. Thorax intense green, the scutellar region blue ; pleura} from above in a certain 

 light silvery-pollinose, in most directions, however, appearing nearly bare. Tegulse deeply infuscated ; 

 halteres brown, the stem lighter. Abdomen with broad black bands, which take in half or more of the 

 last two segments ; hypopygium black, minute, with two slender, curved, yellow appendages, which have 

 somewhat the shape of a parenthesis. Bristles of the body nowhere of striking size and length. Coxae 

 and femora black ; tibiae yellow, all blackened at the extreme base, and the hind ones a little at the tip ; 

 fore tibia) short, bearing a few small bristles in a row on the outer side ; middle tibiae without any 

 noticeable bristles, except one or two very small ones near the base ; hind tibiae with rows of small 

 bristles on the inner side, the outer side comparatively bare. Pore and middle tarsi elongate, slender, 

 plain, infuscated from about the middle of the long first joint. Hind tarsi yellowish at the base, the first 

 two joints very hairy, the next two a little swollen, black, subshining above, the last joint of similar 

 structure, but shorter ; there is a distinct concavity on the underside of the last three joints. Wings with 

 more prominent cross-bands than usual, taking in all the apical half except the interval, which widens 

 behind ; on the basal half the space before the third vein is yellow ; the first cross-band narrowly reaches 

 the hind margin at the tip of the fifth vein. 



Length 6-6-5 millim. 



Hab. Mexico, Teapa in Tabasco, Fortin in Vera Cruz (H. II. Smith). 



Five males. 



10. Psilopus coxalis, sp. n. 



<$ . Face blue, rather narrow, densely white-pollinose ; antennae very small, with minute bristles only ; front 

 pollinose on the lower part and sides, with very few pale hairs. Thorax green, with thin dust, on the 

 sides bright white-pollinose. Tegulse pale at the base, one or two of the uppermost cilia pale ; halteres 

 entirely yellow. Abdomen bright bluish-green, with rather narrow black bands ; there are whitish hairs 

 on the sides ' as far as the fifth segment ; hypopygium small, black, with small, dark, incised, hairy 

 appendages. Fore coxae green, covered with glistening white pollen and white hair, the tip for nearly 

 one-third the length pale yellow. Fore femora with the apical third and a narrow basal portion yellow ; 

 the hairs underneath the pale apex black. Fore tibiae with a few small bristles on the outer or hinder 

 side. Fore tarsi with the first joint long, infuscated and a little enlarged at the tip ; second joint short, 

 thickened, with a pad-like structure on the underside ; third joint short, bent on the second ; fourth joint 

 longer, also bent on the preceding, with a row of fine short bristles underneath ; fifth joint normal ; all 

 the segments beyond the first are black. (Middle legs wanting.) Hind femora black, yellow at the 

 tip ; hind tibiae only moderately hairy, at the extreme apex infuscated ; hind tarsi black (last three 

 joints missing). Wings hyaline, with the usual two . cross-bands ; the space before the third vein on 

 the basal half is yellow, and there is a distinct spot before the small cross-vein ; the cross-bands are 



