164 DIPTEKA. 



and the scutellum of my specimen are denuded, black, shining, with a microscopic punctuation) ; pleurae 

 and pectus also black, and with a similar covering of hair. Abdomen : prevailing colour honey-yellow on 

 the sides, black on the back ; first segment black above ; segments 4-6 deep black on the greater part of 

 the middle ; an irregularly indented border on the sides, yellow ; the dense hairy covering black, with 

 fulvous reflections on the black ground, yellow on the yellow ground ; venter pale honey-yellow ; single 

 segments with broad brown cross-bands in the middle anteriorly, their posterior margins yellow. Tegulse 

 dark brown. Legs brown ; tarsi yellowish-brown, the distal half of the last joint dark brown. "Wings 

 brown, less saturate towards the apex ; venation like Apelleia vittata, Bellardi, but the first posterior cell 

 closed some distance from the margin, and therefore petiolate (see Bellardi, Saggio &c. Append, t. 3. 



fig. 12). 

 Length 14-15 millim. 



Hab. Costa Rica, Rio Sucio (Bogers). 



This species differs from the majority of the other Ocncece in having glabrous eyes. 

 It has this character in common with Ocncea vittata, Bell., and perhaps also with 

 Ocncea tumens, Walk, (at least the figure of the latter shows glabrous eyes ; the letter- 

 press says nothing about them). But from 0. tumens it differs very considerably in 

 the venation, while it agrees in this respect with 0. vittata. From the latter again it 

 differs in the relative length of the third antennal joint, this joint being much longer in 

 0. grossa. This joint is peculiar in structure : it shows, externally, a longitudinal 

 groove, not quite reaching the apex, and thus has the appearance of being folded 

 lengthwise. I do not find any mention of such a structure in other species. 



2. Ocnaea trichocera, sp. n., <? . 



Antennae brown, the second joint yellowish at the tip ; the third joint about five times as long as the first two 

 together, rather narrow, gradually attenuated towards the tip, its upper edge beset with distinct but 

 scattered hairs, a few of which project beyond the tip. Eyes hairy. Thorax, including the scutellum 

 and the callosities, brown, moderately shining, clothed with brownish-fulvous pile. Abdomen brown; 

 hind margins of the segments 2-5 brownish-yellow (the limits of this colour ill-defined), and with a 

 fringe of golden-yellow hair ; the rest of the pubescence black ; on the venter the yellowish hind margins 

 of the segments are narrower, but better defined. Tegulse whitish-yellow, with brown borders. Legs 

 brown ; tarsi paler, except the distal part of the last joint, which is brown. "Wings with a brownish tinge, 

 subhyaline on the proximal third, yellowish along the costa ; the venation is identical with that of 0. grossa, 

 except that the first posterior cell is closed on the margin and therefore not petiolate. 



Length 7-8 millim. 



Hab. Panama, Volcan de Chiriqui 2000 to 3000 feet (Champion). A single male. 



ONCODES. 



Ogcodes, Latreille, Precis des Car. gen. des ins. p. 154 (1796). 

 Oncodes, as amended by later writers. 



I. Oncodes humeralis, sp. n., 6 . 



Humeral and praescutellar callosities and also the pleurae brownish-yellow; legs yellowish-brown, the tips of 



the tarsi darker ; wings subhyaline. 

 Length 4-5 millim. * 



Hab. Mexico, Northern Sonora (Morrison). 



