122 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



Abdoineii ovate, subpetiolate, the second and tliird segments tlie 

 longest, subequal, the following short. 

 Legs as in Ceraphron. 



This genus, as here recognized, dili'ers from Ceraphron in having a 

 stigniated marginal nervure and serrate antennie in the male; and 

 from Lygoeerus and Meympilus in having, at the most, only a single 

 mesonotal furrow. 



Forster characterized the genus as being without trace of a mesono- 

 tal furrow; but, as [ have found to be the case in Aphanogmus, species 

 probably occur with and withtmt a furrow. 



A single species is known in America. 



AtritomuB americanus, sp. nov. 



(PI. VI, Fig.9, <?.) 



S . Length, 1.3""". Black, shining, feebly microscopically punctate; 

 antenn* brown ; legs reddish-brown, the coxie black ; abdomen piceous ; 

 mandibles black or piceous. Head transverse, a little wider than the 

 thorax. Eyes large, oval, bare. Antenuie as long as the body, the 

 pedicel small, triangular, the tirst, second, third, and fourth funiclar 

 joints subserrate, the first the longest, a little more than thrice as long 

 as thick, the following a little shorter. Thorax scarcely narrowed be- 

 fore, with a delicate, central grooved line. Metathorax rounded be- 

 hind. Wing hyaline, pubescent, the stigma large semicircular, reddish 

 brown, the stigmal vein a little longer than the stigma. Abdomen 

 ovate, as long as the thorax, the i)etiole very short, rugose, the second 

 segment occupying about half of the remaining surface, the third and 

 fourth equal, longer than the following, the following very short; clasp- 

 ers flat, distinctly extended. 



Habitat. — Odenton, Md. 



Type S in Coll. Ashmead. 



Described from a single specimen taken by Mr. E. A. Schwarz. 



Tribe II.— Ceraphronini. 



The species in this tribe can always be distinguished from those in the 

 Megaspilini by the linear marginal nervure and the paucity of joints 

 in the female antenna;, the mesonotum, at the most, having bat a single 

 impressed line. • , . 



The genera may be recognized by the aid of the following table : 



TABLE OF GENERA. 



FKMALE8. 



AntennsB 9-jointed 3 



AnteniiiP 10-jointx^d. 

 Wingless forms , 2 



