MONOGRAPH OF THE NORTH AMERICAN PROCTOTRYPID^. 39 



Abdomen entirely rufous. AViugs Siilty white, the stigma and uer- 

 vures hyaline. 



Habitat. — Yuma, Ariz., Montana, Texas, and Virginia. 



Types in Coll. Ashmead, National Museum, and American Entomo- 

 logical Society. 



The males of this species are common, the females rare. 



Both sexes were taken together under stones near an ant's nest, by 

 Mr. Pergaude, August 5, 1885, at Occoquan Falls, Virginia, and a 

 single 9 was taken from the nest of Fonnica ohscuripes at Helena, 

 Mont., by Titus dike. 



Isobrachiiini montanum sp ikiv. 



9 . — Length, 5 """. Head oblong, twice as long as wide, piceous black, 

 punctate, very faintly pubescent. Eyes and ocelli wanting. Mandi- 

 bles rufous ending in 2 black teeth. Antenna' lo-jointed, brownish- 

 yellow, the scape less than half the length of the Hagellum; pedicel 

 longer than the first fuuiclar Joint; flagellar joints, except the first and 

 last, a little wider than long, the last joint oblong. Abdomen much 

 longer than the head and thorax united, pale brownish-yellow. 



(5 . — Length, 4 '"'". Head and thorax black, the collar pale; antennae, 

 mandibles, legs, and abdomen brownish-yellow; wings salty white. 

 The thorax is smooth, impunctured, while the middle grooves of the 

 mesonotum are only slightly indicated anteriorly. jVIetathorax long, 

 smooth, impunctate, the central carina abbreviated. Abdomen longer 

 than the head and thorax together. 



Habitat. — Montana and Arizona. 



Types in Coll. Ashmead. 



The 9 of this species was taken from the nests of Formica rnfihar- 

 bis by H. G. Hubbard at Helena, Mont,, while the male, here associated 

 with it, was obtained from a collection in Arizona; still the structure 

 and color of the abdomen are so similar that there is no doubt left in 

 my mind that they are sexes of the same species. 



Isobrachiuni floridanuni Aslim. 



Ent. Am., in, p. 76; Cress. Syn. Hym., p. 247. 



c5 . — Length, 2.5 """. Black, subopaipie, finely punctate and sparsely 

 covered with a whitish pubescence. Head oblong, closely punctate ; 

 eyes x)ubescent, mandibles long, crossing each other at tips. Antennae 

 13-jointed, ferruginous, covered with a dense pubescence; scape clavate, 

 about half the length of the head ; pedicel not longer than wide at 

 tip, narrowed at base; first flagellar joint a little shorter, the joints be- 

 yond longer. Prothorax trapezoidal, longer than wide across the base; 

 mesonotum very short without furrows; scutellum with a transverse 

 impressed line at base ; metathorax quadrate with numerous longitu- 

 dinal raised lines at base. Wings fusco-hyaline, the nervures brown; 



