AMERICAN IJIPTERA. 281 



black; third joint shorter than the first and second joints taken together, very 

 nearly the length of the first joint; style very short. Mesonotnm shining, me- 

 tallic blue-green, with three deep blue stripes anteriorly, and beset with erect 

 and rather dense brownish black hairs. Abdomen metallic green, with black 

 hair. Hypopygium small, black, with only the base of the filament exposed. 

 Pleurae shining black, metallic blue-green anteriorly, dusted with white poste- 

 riorly. Legs black, covered with black hairs; knees, fore and middle tibiae and 

 all the tarsi yellow. Fore metatarsi thickened, nearly as long as the remaining 

 tarsal joints taken together. Middle legs plain. Hind femora on the inner infe- 

 rior side with two slender finger-like processes, with an emargination between 

 them ; hind tibiae on the inner side with a stout subapical scoop-shaped process, 

 truncated and flattened at the extremity ; hind metatarsi iucrassate, somewhat 

 concave on the plantar side, and bearing on the outer side a prominent pointed 

 projection tipped with two small black spines. Halteres black. Wings tinged 

 with brown, yellowish anteriorly; veins yellow; stigma fuscous, slender aiid 

 inconspicuous; anterior branch of the third vein short, rectangular. 



Female. — Color, especially of the abdomen, more metallic blue. Face shining 

 metallic blue. Middle femora below, hind femora above and below, and the four 

 posterior tibise on their inner and outer sides, with thick-set rows of black scale- 

 like hairs. Middle and hind tibia; grooved on the outer side. Fore metatarsi 

 incrassate, as in the male, hind metatarsi less thickened, and the legs wholly 

 without the peculiar processes of the male. Stigma of the wings obsolete. 4-5 mm. 



Guerrero, Mexico (Smith), 



liamprenipis diapliorina Osten Sacken. 

 Biol. Cent. Am., Dipt. Suppl., 1900, p. '215. 



Female. — Antennae black; third joint elongate, about as long as the first two 

 united, with a short style. Occiput hoary, beset with black pile; front metallic 

 green. Thorax metallic green, shining, with a vestige of three pollinose stripes 

 on the dorsum, the latter sparsely beset with long, erect, black pile; meso- and 

 stcrnopleura shining, metallic green ; pteropleura black, slightly hoary ; the fan- 

 like row of bristles black ; halteres black ; metanotum slightly pulverulent. 

 Abdomen metallic bluish, greenish at the base. Legs brownish yellow, the tips 

 of the tarsi brown ; the first pair beset with moderately long, delicate hairs, their 

 first tarsal joint long, swollen ; on the middle pair the hairs are shorter and more 

 dense, fringe-like, especially on the underside of the femora; the hind tibite are 

 broad and flattened, and bear on each side a fringe of long, stout, almost scale- 

 like hairs; similar fringes on the hind femora, but less conspicuous; coxae black ; 

 trochanters brown. Wings with a pale brownish yellow tinge toward the root of 

 the anterior margin; stigma hardly visible ; hind margin grayish; the branch 

 of the third vein nearly perpendicular; the first vein issuing from the discal cell 

 turning anteriorly before its end ; the first and second veins reach the margin, 

 but are very thin and evanescent before it. Length about 4 mm. 



Ciudad in Durango, Mexico. 



LiainprenipiM benigna Osten Sacken. 

 Biol. Cent. Am., Dipt. Suppl., 1900, p. 215. 



Male and Female. — Antennae black ; third joint a little shorter than the preced- 



TBANS. AM. ENT. SOC, XXVIII. (3ti) AUGUST, 1902. 



