RIIACHICERUS. 105 



facets, deeply notched and including- a smooth space on each side 

 by the base of the antennae. Ocelli approximate. Proboscis not 

 prominent ; palpi short. Antennae with 34 or 35 joints, tapering 

 slightly, much more than half the length of the body, deeply 

 serrated on each side; joints transverse, very short, cyathiform, 

 petiolated. Thorax elongate -quadrate ; abdomen pubescent, 

 8-segmented, hardly tapering from base to tip, about twice as 

 long as thorax. Legs rather slender, moderately long ; hind 

 tibia? with very minute spurs ; ungues and onychia very small. 

 Wings narrow." 



Range. North and Central America, Ciil)n. Tiulia, INIalay Archi- 

 pelago, and one species in Europe. 



Life-history unknown. 



Table of Species. 



Thorax orange nit/riconiis, sp. ii., p. 10.5. 



Thorax black. 



Dorsum of first three abdominal segments 



mainly yellow bicolor, Rrun., p. 105. 



Dorsum of abdomen all black, except a 



transverse yellow band on 2ud segment, wiicincta, sp. n., p. 100. 



68. Ehachicerus bicolor, Bmn. 



Rhachicerns hicolor, Brunetti, Ree. Ind. Mus. vii, p. 461 (1912). 



$ . Head with frons nearly one-third width of head, shining 

 black, bare ; three small yellow ocelh at vertex ; eyes blackish, 

 bare; proboscis bright yellow, palpi of similar colour, verv small ;' 

 a whitish triangular spot on each side between the eves and the 

 base of the antennae. Antennal 1st and 2iid joints black, 2nd 

 with a circlet of black and yellow bristles around its tip ; flagellar 

 1st joint mucli wider than the rest, which are blackish brown, the 

 comb-like prolongations on the underside bright yellow. (The 

 antennae being incomplete, the exact number of joints cannot be 

 given.) Thorax and scutellum wholly shining black, practicallv 

 bare ; humeri conspicuous, bright yellow. Abdomen black, dorsum 

 of first three segments mainly yellow, the borders being black, the 

 4th segment being more or less yellow in the centre ; venter 

 principally yellow on the first three segments, remainder blackish. 

 Legs bright yellow, hind coxae black. Wings with venation as in 

 XyJomyia, grey, with a hardly perceptible darkening from the 

 costa partly across the wing, and again towards the tip; halteres 

 bright yellow. 



Lengthy 8^ mm. 



Described from one $ in good condition in my collection from 

 Kandy, v. 1909 {E. E. Green). 



69. Rhachicerus nigricornis, sp. nov. (PI. II, fig. 1.) 



6 . Head black ; frons at vertex less than one-fourth width of 

 head, widening to one-third at level of antennae, \\ith some 

 whitish dust around b:ise of antennae ; scape of latter yellow, with 

 short black bristles, Hagellum black for 23 joints, with the comb- 



