[2 1 7] HYMENOPTERA 223 



Genus Polyterus Forster. 

 POLYTERUS SEXCARINATUS sp. nov. 



Female. Length 8.5 mm. Black ; clypeus and mandibles dark 

 rufous ; palpi yellowish, with the two basal joints brownish or fuscous ; 

 legs, except the hind tibia? and tarsi, including tibial spurs ferruginous, 

 hind tibiae, their spurs and tarsi black. Head coriaceous opaque ; 

 thorax above shining, although microscopically punctate, the meta- 

 thorax wrinkled but shining, and with six longitudinal carinas, the two 

 middle rather close at their origin but diverging posteriorly and uniting 

 with the transverse apical carina, the space between being transversely 

 rugulose and twice as wide at apex as at base. Wings hyaline, or 

 only faintly tinged, the stigma and veins brown. 



Type. Cat. No. 5651, U. S. Nat. Museum. From Alaska (U. S. 

 Coast and Geodetic Survey). Two specimens. 



Genus Hyposyntactus gen. nov. 



In a table of genera this new species will fall next to Syntactus 

 Forster. The two may be separated as follows : 

 Clypeus with a transverse furrow at apex. 



Metanotum -without median carinse ; hind legs long, their tarsi thickened, the 

 longer spur of the tibiae not or rarely half the length of the basal tarsal 

 joint; disco-cubital nervure not broken by a stump of a vein Syntactus. 



Metanotum -with two median carinse forming an areola, which, however, is 

 open at base ; hind legs normal, the longer tibial spur of hind legs fully 

 half the length of the basal tarsal joint ; disco-cubital nervure angularly 

 broken by a stump of a vein Hyposyntactus. 



HYPOSYNTACTUS FLAVIFRONS sp. nov. 



(PI. x, fig. 4 .) 



Male. Length 10 mm. Black; face below antennae, mandibles, 

 scape beneath, a line on collar above, a triangular spot on each side of 

 the mesonotum anteriorly at the base of the parapsidal furrows, the 

 tegulae, hypo- and epitegulaa, a line beneath, a dot on each side of the 

 prosternum in front of the front coxae, a spot on mesoternum, the 

 front and middle legs, the hind trochanters, basal two thirds of hind 

 tibiae and their tarsi except last joint, and dorsal abdominal segments 

 2, 3 and 4, except narrowly at apex, lemon-yellow. Wings hyaline, 

 the stigma within yellowish, outwardly as well as the internal veins, 

 brown, the disco-cubital nervure angularly broken by a stump of a vein 

 before the middle. 



