1901] Melunder — The Genus Tachi/dromia 59 



scutellum with four black bristles; acrostichal and dorsocentral bristles 

 microscopic; hypopygium large, flexed to the right. 



Front narrowly V-shaped, cinereous; ocelli large, ocellar bristles present, 

 black; first antenna! joint testaceous, the outer joint fuscous, pubescent, 

 arista subterminal, pubescent, four times the length of the antenna. Eyes 

 completely contiguous on the face, facets uniform. Palpi twice as long as 

 broad, sericeous, testaceous. Proboscis slender, vertical, piceous, one-half 

 the height of the head. Occiput and entire thorax rather lightly covered with 

 cinereous pollen; humeri comparatively small and not so deeply constricted 

 as in the other species; the usual black bristles present along the sides of the 

 notum; scutellum with two long decussating and two short bristles; acro- 

 stichal and dorsocentral rows of minute whitish bristles present, with about 

 six bristles to each row, the last dorsocentral large; no pleural hairs. AI3- 

 domen brown-black, sub-shining, last segments black hairy; hypopygium 

 large, globular, flexed to the right. Coxae shining yellowish, legs yellowish, 

 femora dusky on the outer half, legs provided with short white bristly hairs, 

 middle tibiae with series of minute black setulae beneath, front femora much 

 thicker than the others. Halteres dusky. Wings clear hyaline, veins strong, 

 hind margin ciliate; first posterior cell ending at wing tip, and there somewhat 

 contracted, marginal cell a little longer than the submarginal along the costa. 



Described from a single specimen labeled, Grenada, W. I., reeeivtd 

 from Prof. J. M. Aldrich. 



Tachydromia agens sp. nov. 



Male and fetnaJe. Length 1.3 mm. Head and thorax pruinose, legs dark 

 fuscous, wings clear hyaline; antennae blackish; palpi sub-quadrate, pale; 

 acrostichal and dorsocentral bristles conspicuous, scutellum with four white 

 bristles; hypopygium terminal. 



Front broad above, narrow and sub-parallel below, cinereous; ocelli small, 

 ocellar bristles small; occiput lightly pollinose, its cilia white and conspicuous; 

 antennae small, black, the basal joint blackish, arista almost terminal, short, 

 although four times the length of the antenna, microscopically pubescent. 

 Eyes completely contiguous on the face, deeply but narrowly excised at the 

 antennae, facets nearly uniform, those below larger. Palpi of male yellowish, 

 one-half longer than broad, with three long terminal white hairs, in the female 

 the palpi are dusky but with a white sheen. Proboscis black, no longer than 

 the palpi, projecting somewhat forward. 



Thorax cinereous pollinose, humeri round, not quite as broad as the inter- 

 humeral space, the furrow not deep except behind; all the thoracic bristles 

 white, the acrostichal and dorsocentral rows well developed, the lateral bristles 

 comparatively short, about a dozen in front of the wings" scutellum with two 

 long and two short white bristles; no pleural bristles. Abdomen sub-shining 

 olivaceous black, with sparse stubby whitish hairs, the lateral margins of the 

 intermediate segments with the round black pits characteristic of Coloboneura, 

 Parathalassius, etc. Hypopygium closed, terminal, elongate. Coxae shining. 



