MONOGRAPH OF THE NORTH AMERICAN PROCTOTRYPID.E. 35 



Habitat. — United States. 



Type: 9 in Berlm Museum; S in National Museum audC'oll. Amer- 

 ican Ent. Soc. 



The type of Scleroderma eontracta Westw. I have seen in the Berlin 

 Museum ; it has 3-dentate and not ^-dentate mandibles, as described by 

 Westwood. 



The species is widely distributed over the United States, but the 5 

 is rare. Specimens are in my collection from Florida and Iowa, while 

 the National Museum and the American Entomological Society have 

 specimens from Texas, Georgia, Virginia, Maryland, and other States. 



ISOBRACHIUM Funster. 



Hym, Stud., ii, p. 96 (1856). 



(Type /. {Omol us) fuscicornin Nees.) 



Head in 9 much elongated, more rounded in S , the cheeks posteriorly 

 delicately margined; eyes in 9 wanting or very minute, in $ rather 

 large, reaching to the base of the mandibles; ocelli absent in 9 , present 

 in the S . 



Antennae 13-jointed, filiform, inserted in a clypeal fovea, the scape 

 curved. 



Maxillary palpi 6-jointed; labial palpi 4-jointed. 



Mandibles broadened and truncate at apex, in S with an acute outer 

 tooth and with usually 4 small blunt dentations within; in 9 with 3 

 teeth, the outer two most frequently equal. 



Thorax in S similar to Epyris, the prothorax rounded anteriorly, the 

 mesonotal furrows rarely complete, most frequently indicated only an- 

 teriorly, sometimes entirely wanting; there is also a distinct groove on 

 the shoulders; metathoraxlong; in the 9 the thorax between themeso- 

 and metathorax is strongly constricted and the scutellum is wanting. 



Front wings in S very similar to Upyris, only the stigma is smaller, 

 more quadrate, the transverse median nervure usually more oblique, 

 not so distinctly curved, while the discoidal nervure is present and the 

 second discoidal cell is more or less present; the 9 is always apterous. 



Abdomen ovate, depressed, the segments unequal; in 9 elongate, 

 conic ovate. 



Legs as in Pristocera, not much thickened in the S ; tarsi longer 

 than their tibiic, the basal joint of posterior tarsi as long as the re- 

 maining joints united; in the 9 the middle tibiiP, are spinous. 



This genus bears a superficial resemblance in the nnile sex to both 

 Mesitins and Upi/ris, but the nuich slenderer legs, eyes extending to 

 base of mandibles, and the 4-jointed labial palpi readily distinguish it 

 from those genera. The female comes nearest to Pristocera, but the 

 absence of a scutellum and the strongly constricted metathorax suf- 

 ficiently separate it from it and other wingless forms. 



