244 MEMOIRS OF THE CARNEGIE MUSEUM 



15. Front femora much swollen, the hind femora finely serrate beneath ; antennse with 2 ring-joints. 



Plesiostigmodes Ashmead, g. nov. (type P. hrasiliensis Ashm.). 

 Front femora normal, the hind femora finely serrate beneath and often with a tooth ; antennse with 1 

 ring-joint. 



Stigmal vein distinct, its knob always petioled , Cryptopristus Forster. 



Stigmal vein very short, its knob sessile Hemitorymus Ashmead. 



16. Antennse inserted close together. 



Antennae 2-jointed, the second clavate (dimorphic form) Plesiostigma Mayr, Nannocerus Mayr. 



Antennse 4- to 7-jointed ; thorax not depressed ; hind femora with 2 teeth beneath towards apex ; 

 hind tibise with spines only at base of tarsi (dimorphic form). Physothorax Mayr. 



Subfamily IV. PoDAORiONiNiE. 



This group in having the hind femora greatl}^ swollen and dentate beneath, with 

 the hind tibise curved, resembles the Clialcididx, but otherwise, in the structure of 

 head, side pieces of the thorax, coxse, and in venation, it is a genuine Torymid, and I 

 have here removed it from the CJialcididx, where late authorities have placed it, to a 

 place in this family. 



The genus Podagrion is parasitic in the egg-cases of the orthopterous family 

 Mantidse. 



TABLE OF GENERA. 

 Stigmal vein not so short, the knob petiolate ; tarsal joints 2-5 very short, transverse, the first joint long ; 



hind femora armed with 4 teeth Pachytomus Westwood (type P. klugianus Westw.). 



Stigmal vein very short, the knob subsessile ; tarsal joiats 2-5 not short ; hind femora armed with from 6 



to 8 teeth Podagrion Spinola (type P. splendens Spinola). 



Subfamily V. Megastiumin^e. 

 1875. Megastigmides, Subtribus, Thomson, Skand. Hym., IV., p. 59. 

 1899. Megastigminse, Subfamil}^ IV., Ashmead, Froc. Ent. Soc. Washington, IV., p. 

 246. 



The species falling in this subfamily are easily recognized by the large circular 

 or rounded knob of the stigmal vein. 



Species of the genus Megastigmus are bred commonly from hymenopterous and 

 dipterous gall-makers [Oyniindx and Cecidomyiidse) and also from the seed capsules 

 of various trees and plants. The group is, therefore, phytophagous as well as para- 

 sitic. Megastigmus spermcdotrjplius Wachtl was bred from the seed of the Douglas 

 spruce, Pseudotsuga douglasii. It is identical with 31. pinus Parfitt, also bred from 

 the seed of a pine and described thirty-six years earlier. 



table OF genera. 



1. Head and thorax smooth or transversely wrinkled or aciculate ; mandibles 3-dentate 2 



Head and thorax neither smooth nor transversely wrinkled or aciculate, but sj^arsely or very finely 

 punctate ; mandibles 4-dentate. 



