14 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 7» 



MINETTIA ARGENTIVENTRIS, new species 



Male. — Head brownish black; frons velvety black, more brownish 

 on orbits and a narrow central vitta, and with grayish dust at bases 

 of the bristles; antennae brownish yellow; aristae fuscous, paler at 

 bases; face slightly white dusted; occiput testaceous on each side of 

 lower half, and with whitish dust; palpi fuscous. Thorax deep 

 brownish black, almost velvety on dorsum, and when seen from the 

 side and in front with dark vittae; some slight whitish dust round 

 prothoracic spiracle; margin of the scutellum more brownish than 

 disk and slightly shining. Abdomen brown, first to third visible 

 tergites with white, almost silvery, dusting which is not very dense,. 

 and is most conspicuous when viewed from in front. Legs dark 

 brown, the tarsi except their apices testaceous. Wings yellowish 

 hyaline, black at extreme bases and on costal vein at apex of 

 auxiliary vein. Halteres yellow. 



Frons subquadrate, anterior orbitals hardly more than half as long 

 as posterior pair, ocellars very short and fine, postverticals short; 

 third antennal segment fully twice as long as wide, slightly nar- 

 rowed at apex ; arista plumose ; face with a slight but distinct hump 

 on each side below ; palpi broad. Thorax with two pairs of strong 

 postsutural dorsocentrals, one pair of prescutellar acrostichals, about 

 12 series of intradorsocentral hairs, one sternopleural, the prosternal 

 plate broad and with microscopic hairs, the scutellum convex, rounded 

 in outline, and with four bristles, the basal pair incurved, the apical 

 pair divergent. Abdomen stout, apices of tergites 2 and 3 bristled. 

 Legs normal, no anteroventral comb on fore femur. Inner cross 

 vein at about three-sevenths from base of discal cell, penultimate 

 section of fourth vein subequal to ultimate, the latter slightly for- 

 wardly sloped apically. 



Length, 6 mm. 



One male, near Para, Brazil (Miss H. B. Merrill). 



Type.—Q^X. No. 40711, U.S.N.M. 



This species is readily distinguished from any black one by the 

 white-dusted abdomen and its large size. It belongs to the segregate 

 containing the genotype, in which there are two slight but evident 

 humps on lower portion of the face. 



MINETTIA INFUSCATA, new specUs 



Female. — Head black, subopaque, slightly shining on frontal or- 

 bits, with pale gray dusting, most dense on face; antennae fuscous, 

 base of third segment yellowish below; palpi fuscous. Thorax 

 black, shining, the dorsum evenly and slightly gray dusted, and with- 

 out vittae, pleura more densely gray dusted. Abdomen shining 

 black, hardly dusted. Legs testaceous yellow, whitish dusted, femora 



