DIPTERA. 81 
BiastEs rnpicus, Plate 3, fig. 3. 
Mas. Niger, scutelli margine postico fulvo dentibus quatuor fulvis ornato, 
antennis piceis basi fulvis, pedibus fulvis, tarsis flavis, femoribus pos- 
licis piceis, alis subcinereis ad costam apice fuscis. 
Male. Body black, dull, without hairs, but covered with very short 
tawny down: face tinged with white: eyes bronzed, occupying the whole 
upper side ; facets large above, very small in front: mouth tawny: feelers 
pitchy, tawny at the base: chest long and narrow, convex, spindle-shaped ; 
hind border of the scutcheon tawny, armed with four short tawny teeth : 
abdomen elliptical, finely punctured, much broader but not longer than 
the chest: legs tawny; feet pale yellow; hind thighs pitchy : wings pale 
gray, brown beneath the tip of the fore border; wing-ribs and brands 
tawny; veins strongly marked, in structure like those of Clitellaria, pitchy, 
tawny along the fore border ; poisers pitchy. 
Fem. Eyes parted by a moderately broad interval, which is smooth 
and shining ; all the facets very small: head very slightly lobed above on 
each side behind the eyes. 
Length of the body 3 lines ; of the wings 5 lines. 
? 
METABASIS, n. g. 
Caput anticum valdé productum, conicum: antennis articulus lus 
subfusiformis ; 2us obconicus, li longitudine ; 3us et sequentes areté co- 
herentes, articulum unicum fusiformem 20 feré quadruplo longiorem quasi 
fingentes, 
Front of the head produced into a slender cone, which is as long as 
the preceding part and bears the feelers on its tip: first joint of the feelers 
nearly spindle-shaped ; second obconical as long as the first; third, and all 
the following forming a compound, indistinctly divided joint, nearly four 
times the length of the second joint, and of a lengthened spindle-shaped 
form. 
Merasasts rostratus, Mas. 
Niger, thoracis lateribus viridi vittatis, scutelli margine postico ferrugineo 
dentibusque duabus ferrugineis armato, antennis nigris apice picers, 
pedibus ferrugineis, tarsis piceis, alis nigro-fuscis. 
Body black, long and narrow, rather flat: head shining, tawny beneath ; 
its cone slightly furrowed across: eyes red, nearly meeting on the crown, 
