342 Professor Aldricli on the 



destitute of large bristles. Wings slender, hyaline. Costa 

 noticeably ciliated along the middle, in the neighbourhood of the 

 first vein. Third vein at its tip recurved forward. Posterior 

 cross-vein oblique, less than half its length from the border. Fork 

 of fourth vein making scarcely a right angle at its origin. 



$ . Thorns of the fore femora larger. Middle tibiae and tarsi 

 simple. Abdomen, except the first segment, with more green on the 

 dorsum, and shorter than in the male. 

 Length 4'5 mm. ; of wing, the same. 



Sea level to 500 feet. Six males and eight females. 



3. Onamptopsilopiis flavicorms, n. sp. 



5 . Small, bright green, base of abdomen yellow, antennae, 

 yellow, the third joint sometimes brownish, arista dorsal or sub- 

 dorsal. Face moderately narrow for the genus, blue or green, 

 white-dusted. Front shining green, excavated, dusted below. 

 Antennaj yellow, the third joint sometimes brownish ; the arista 

 ■dorsal or subdorsal. Thorax bright green. Scutellum with two 

 large bristles, the outer pair minute, oppressed, or absent. 

 Pleurte green, white pollinose, the posterior border yellow. 

 Tegulaj and halteres yellow. Abdomen green, the venter dorsum 

 of first and proximal half of second segment yellow. Still in some 

 ■cases the posterior margin of the first segment green. On the 

 lateral angle of the first segment one or two long black bristles. 

 Remainder of abdomen with small sparse black hair. Legs in- 

 •cludiug coxfe, yellow, the tarsi slightly infuscated. Fore coxa3 with 

 three yellow bristles, hind with one. Fore metatarsus scarcely 

 shorter than tibia, middle one but little shorter, whole hind tarsus 

 four-fifths the length of its tibia. The legs have no bristles of 

 any size ; at the tips of the middle and hind tibiae, and on the fore 

 ■side of the same near the base are very small ones. Wiugs 

 hyaline, the veins yellow ; third vein recurved at tip, branch of 

 fourth vein making a right angle at its origin. Posterior cross- 

 vein oblique, two-thirds its length from the margin. Length 

 1'8 mm. ; of wing, 2 mm. 



Three females. One specimen has the third joint of 

 the antennge brownish-black, and the outer pair of 

 «cutellar bristles visible though minute, the other two 

 have the antenna wholly yellow, and no second pair of 

 bristles whatever. This does not seem to indicate a 

 specific diti'ereuce. 



