BBACHYCISTIS. 397 



2. Brachycistis dubitatus. 



Long. 13 millim. $ . 



Hab. Mexico, Northern Sonora {Morrison). 



The head is nearly as wide as the mesothorax, shining, impunctate, deep black, the 

 clypeus obscure testaceous, the mandibles piceous, black at the apex ; covered with 

 white hair ; rounded behind, and developed there about one-third of the length of the 

 eyes ; on the outside the ocelli are surrounded by a furrow, and there is a shallow 

 indistinct furrow joining the hinder pair behind. The antennas reach beyond the 

 apex of the thorax ; the scape with some white hairs ; the flagellum almost bare, 

 tapering a little towards the apex ; the third and fourth joints subequal. The thorax 

 is shining, impunctate, sparsely covered with long soft white hair, the hair on the 

 scutellum longer than on the other parts ; the lateral furrows on the mesonotum 

 narrow, but distinct ; the scutellum very slightly narrowed towards the apex. The 

 median segment has a gradually rounded slope, shining, impunctate ; the basal area 

 long, not very distinctly traced, the apex reaching nearly to the middle of the segment. 

 The pro- and mesopleurse shining, punctured, but not strongly, the base and apex 

 impunctate ; the metapleurse impunctate, except at the extreme apex. The petiole is 

 slightly longer than the second segment, gradually dilated to beyond the middle, 

 shining, impunctate, covered with long, soft, white hair ; the other segments are 

 impunctate, sparsely covered (especially towards the apex) with long white hair ; the 

 apical segment is broadly raised in the centre, the sides with large rounded or oval 

 punctures. The bottom of the petiole is bluntly keeled in the centre, covered with 

 some large punctures; the edges furrowed. The other ventral segments shining, 

 impunctate, sparsely covered with long pale hairs. The legs are sparsely covered with 

 long white hair, the hair being much shorter and closer on the tarsi ; the spurs do not 

 reach to the middle of the metatarsus. The wings are shorter than the body, reaching 

 nearly to the apex of the fourth abdominal segment, clear hyaline ; the stigma black ; 

 the nervures blackish at the base of the wings, much paler towards the apex ; the 

 radial cellule wide, shorter than the stigma ; the basal abscissa of the radius oblique, 

 issuing a little beyond the middle of the stigma, the apical abscissa straight and paler 

 in colour ; the transverse basal nervure interstitial ; at the top, the first and second 

 transverse cubital nervures almost unite ; the first recurrent nervure received near the 

 basal third of the cellule, the second near the middle. 



3. Brachycistis vigilax. 



Long, fere 12 millim. J . 



Hab. Mexico, Northern Sonora [Morrison). 



The head black, the apex of the clypeus and the mandibles piceous, the latter 



