168 BULLKTIN ir., UNITED S'l'ATK!^ NATIONAL MUSEUM. 



Mesonotuni without furrows; lateral ocelli close to the iiiarjiin ol' the ej'e. 

 Auteuua' tilit'oriu, u ion ill form, or snbiiioiiijiforiii. 

 Basal jiervnre distinct; mandibles bifid. 



Head miicli liroader than the thorax; eyes bare; anteuu;e tapering toward 

 ayiex; basal abdominal segment as wide as the inetathorax. 



AcoLUS Fiirster. 



Head siil)qnadrate, bnt slightly broader than the thorax; antenna" slightly 



thickened toward apex; basal abdominal segment petiolitbrra, much 



narrower than the metathorax Bakis Haliday. 



Basal iiervui'e wanting; mandibles tridentate. 

 Head ti'ansverse, scarcely broader than the thorax; eyes hairy; antennae 

 slightly thickened at tip; basal abdominal segment transverse, not 

 quite as wide as the apex of metathoiax Acoloides Howard. 



THORON Halidiy. 



Ent. Mag., i, p. 271 (l«:tt); Foist. Hym. Stud., ii, p. 100 (1856). 



(Ty]ie 1'. fiiniicalns Nees. = T. vtttaUhiiK Hal.) 



Head rather large, tran.sverse, the oceii>ut aud eheeks margined; 

 ocelli 3, triangularly arranged, and wider apart than in Prosacaittha; 

 eyes large, oval. 



AnteunjTp inserted close to the elypens, 12-iointed in both sexes; in 9 

 clavate, the clnb solid, althongh showing traces of sutures; in S long, 

 liliform, the pedicel small, oval, the flagellar joints nearly equal, about 

 4 times <is long as thick, pubescent. 



Maxillaiy pali»i 4-jointed; labial palpi L*-jointed. 



Mandibles tri<lentate. 



Thorax ovoid, the prothorax visible from above as an arcuate line, 

 depressed anteriorly; mesonotum with 2 impressed lines; metathorax 

 very short, rounded at the sides. 



Front wings with the submarginal vein joining the costa behind the 

 middle; the marginal vein very short, thickened; postmarginal vein 

 not, or scarcely, developed ; the stigmal vein longer than marginal, thick- 

 ened at base, and terminating in a little knob. 



Abdomen oval or oblong-oval, strongly narrowed at base, the tirst 

 segment longer than wide, the third the longest. 



Legs long, slender, pilose, the femora clavate, the tibiie subclavate, 

 with spurs 1, 1, 1; the tarsi very long and slender. 



Thoron pallipes Ashm. 

 (ri.xvi,Fig..S, 9.) 

 Ent. Am.. Ill, p. 99. 



9. Length, 2""", Black, polished; head subquadrate, smooth, the 

 face convex; mandibles bluntly 3-dentate at tii)s, pale rufous. Meso- 

 notum sparsely punctate, with 2 furrows posteriorly; metathorax and 

 pleura rugose. Antennae 12-jointed, dark brown, the scape and pedi- 

 cel brownish-yellow. Legs, including coxic, pale or yellowish. Abdo- 

 men oblong-oval, a little longer than the head and thorax together, 

 attached high up on the metathorax, the first .segment petioliform, 



