396 HYMENOPTEEA. 



1. Brachycistis tysias. 



Long. 14 millim. tf . 



Hah. Mexico, Northern Sonora (Morrison). 



The head as wide as the thorax, almost impunctate, in some specimens with a 

 few long pale hairs, rounded at the sides posteriorly, the space behind the eyes 

 not half their length ; deep black, shining, the face between and below the antennae 

 ferruginous ; the mandibles ferruginous, the tips black ; the clypeus is dilated in the 

 middle ; behind the ocelli is a deep transverse furrow ; the eyes are margined behind. 

 The antennae reach slightly beyond the thorax ; they taper towards the apex ; the scape 

 has long white hair; the flagellum is glabrous; the third and fourth joints are sub- 

 equal. The pro- and mesonotum have longish soft pale hairs ; shining and sparsely 

 punctured ; the lateral furrows on the mesonotum do not extend to the base ; the 

 scutellum has a few punctures on the sides. The median segment is shining, slightly 

 shagreened ; the apex somewhat oblique and covered with soft white hair, the basal 

 half being almost glabrous ; at the base in the middle are two short furrows, which 

 unite at the apex and run into a furrow which proceeds down the centre to near the 

 apex of the segment. The propleurae are punctured, except round the sides at the 

 base and apex ; the mesopleurae are still more strongly and closely punctured, except 

 at the apex, which bears hardly any punctures ; the metapleurae are slightly hollowed, 

 smooth, and impunctate, except at the apex. The petiole is as long as the second 

 segment, shining, covered with long white hair; the basal third narrowed, the 

 remaining part gradually thickened towards the apex and almost impunctate ; beneath 

 it is coarsely shagreened, the sides and the centre furrowed. The other abdominal 

 segments are smooth and shining, bearing long white hair, the hair becoming longer 

 and closer towards the apex. The apical ventral segments are more or less blackish. 

 The legs are of a nearly uniform rufous colour, except that the tibiae and tarsi may be 

 a little paler in tint ; they bear long white hair. The wings hardly reach to the apex 

 of the abdomen, clear hyaline, except that beyond the radial cellule, along the costa, 

 there. is a faint narrow cloud ; the stigma and the basal and radial nervures are black, 

 the other nervures paler ; the base of the costa is white. The radial cellule is shorter 

 than the stigma ; the basal abscissa of the radius curved, the apical abscissa straight 

 and with a short branch at its base ; the transverse cubital nervures are pale and 

 bullated, the first and second nearly uniting at the top, the space bounded by them 

 being less than the space bounded by the first transverse cubital and the first recurrent 

 nervures ; the first recurrent nervure is received in the basal third of the cellule, the 

 second near the middle ; the transverse basal nervure is interstitial ; the recurrent 

 nervures are curved, the second very pale. 



