464 FROVEEDINOS OF THJH NATIONAL MUtiEUM. vol.54. 



Length at least 2.7 mm. ; the head and thorax measure 2.1 mm. in 

 length and 0.8 mm. in breadth. Color, dark brown; eyes, black; 

 antennae, light brown; elytra and abdomen still lighter; legs, trans- 

 parent yellow. 



Head, broad; eyes, many faceted, on broad bases; head deeply 

 emarginate between eyes with occiput strongly projecting from the 

 emargination and antennae set on the sides of the prolongation. 

 Front triangularly projecting beneath attachment of antennae. An- 

 tennae with second joint shorter than first and ringlike. They are 

 not different from the usual Xenid type. Mandibles elongate, ensi- 

 form. Maxillae two- jointed, the first longer. Pronotum transverse, 

 slightly arched forward. Mesonotum with a small anterior detached 

 piece ; the posterior angles strongly produced ; pleural spiracular lobe 

 beneath elytra of the same shape as in Xenos. Metathorax of the 

 usual size. Praescutum keystone-shaped. Scuti broadest behind the 

 base at the attachment of the wings; narrowly separated medianly 

 by the scutellum ; divided to form diagonal parascutellum. Scutellum 

 elongate, pedunculate at posterior angles, triangularly produced in 

 front between scuti, rounded at apex; postlumbium transverse, 

 wrinkled, not heavily chitinized; postscutellum elongate, normal. 

 Wings with the normal veins, and two small detached pieces beyond 

 tip of radius. Oedeagus as in Xenos. (See pi. 72, fig. 7.) 



This is the first male of the genus for America and the first seen by 

 the writer. Whether our American species are congeneric with the 

 European can not yet be determined. 



Type.— Cut. No. 21449, U.S.N.M. 



21. Genus MONOBIAPHILA Pierce. 



1. M. hishoppi Pierce; parasite of Monohia quadridens Linnaeus, 

 Texas. 



3. Tribe TACHYTIXENINI Pierce. 



22. Genus TACHYTIXENOS Pierce. 



1. T. indicus Pierce; parasite of I'achytes xenoferus Rohwer; 

 India. 



4. Tribe OPHTHALMOCHLINI Pierce. 

 Table of genera. 



Female cephalothorax widest behind spiracles, more or less evenly convex 

 throughout ; spiracles dorsal. Male scutellum not locked by the scuti ; post- 

 lumbium not of a different consistency from the other parts. Parasites of 

 Sphex, Psammophila, and Miscus 23. Eupathocera Pierce. 



Female cephalothorax broader than long, margins irregularly convex, con- 

 stricted at base, rounded at apex. Male scutellum locked by scuti ; postlum- 

 bium of a different consistency from the other parts. Parasite of 

 Chlorion 24. OpMliahnochlus Pierce. 



