ASHMEAD : CLASSIFICATION OF THE CHALCID FLIES 233 



The males in this subfamily are easily distinguished from those in the next by 

 the shape of the abdomen, which is always long and tubular, narrowed toward apex 

 and never broadened at apex as in the Sycophaginse. It is also more flexible and is 

 usually curved or bent forward under the thorax. 



The females are more difficult to separate and, although with practice one can 

 detect a difference in cephalic characters, almost impossible to define, the only reli- 

 able character to separate them from those in the other subfamily is the mandibular 

 appendage, which is usually finely serrate. . In the Sycophaginse the mandibles are 

 always without an appendage. 



The known genera falling in this group may be easily recognized by the use of 

 the following table : 



TABLE OF GENERA. 



1. Females, always winged 2 



Males, always apterous 10 



2. Antennse with the third or foui-th joint with a distinct process 3 



Antennae without a joint with a distinct proces 9 



3. Front wings with the marginal, stigmal and postmarginal veins fully developed, or at the most with 



the postmarginal vein absent 4 



Front wings without marginal, stigmal and postmarginal veins. 



Head oblong, about IJ times as long as wide ; antennse 11-jointed, thickened toward apex. 



Eupristina Saunders (type E. masonii Saund.). 



4 Postmarginal vein present .' 5 



Postmarginal vein absent 7 



5. Antennse 11 or 12-jointed 6 



Antennse 10-jointed, the last five joints enlarged Kradibia Saunders (type K. cowanii Saunders). 



6. Head not very long, quadrate or nearly so 8 



Head oblong, or very long, from 2i to 3 times as long as wide, the facial channel narrow ; mandibles at 



apex bidentate ; antennse 11-jointed Pleistodontes Saunders (type P. imperialis Saunders). 



7. Head quadrate or nearly, only a little narrower in front than behind ; stigmal vein usually a little 



longer than the marginal Eisenia Ashmead gen. nov. (type E. mexicana Ashm.). 



8. Seventh abdominal segment on each side with a small rounded or at most oval, spiracular fovea. 



Blastophagus Gravenhorst (ty^pe Cynips psenes Linn6). 

 Seventh abdominal segment on each side with an elongate, disk-shaped, spix-acular fovea. 



Ceratosolens Mayr (type C. appendiculatus Mayr). 



9. Front wings with the marginal, stigmal and postmarginal veins wanting ; head trapezoidal, a little 



longer than wide ; antennse 11-jointed, not thickened towards apex, the joints smooth ; middle legs 



very minute or subobsolete Tetrapus Mayr (type T. americanus Mayr). 



Front wings with the marginal, stigmal and postmarginal veins present ; head oblong, 2J times as 



long as wide; antennse (?) 12-jointed, the scape large, triangularly dilated, the funicle slender, 



filiform, the club abruptly enlarged, 3-joiuted ; mandibles 3-dentate ; thorax bidentate at each side. 



Agaon Dalman (type A. paradoxum Dalm.). 

 10. Head anteriorly with a large, deep, triangular fovea. 



Basal part of antennae enclosed in a canal . . 11 



Basal part of antennse not enclosed in a canal 12 



