No. 2315. TRIBES OF WHNEUMONINAE—CUSHMAN AND ROHWER. 395 



monini. The only described genera occurring in this region which 

 belong to this tribe are Rhyssa Gravenhorst and Megarhyssa Ashmead, 

 but in other parts of the world others occur, and all the genera treated 

 by Morley in his tribe Rhyssides appear to belong to the Rhyssini as 

 here defined. 



Through Apechoneura Kriechbaumer it is related to the Labenini, 

 and, through certain genera of the Xoridini and Ichneumonini to 

 those tribes. 



Tribe ACOENITINI. 



As here restricted this tribe embraces only those genera which, in 

 the female, have the hypopygidium very long vomeriform and 

 polished. In the Holarctic fauna this includes, of the genera which 

 we have examined, only Arotes Gravenhorst, Coleocenfrus Graven- 

 horst, Acoenites Latreille, Phaenolohvs Foerster, and Mesoclistus 

 Foerster. 



Of the genera placed in this tribe we have not had opportunity to 

 examine Asthenomeris Foerster. The type of Asthenomeris has never 

 been described; but according to Schmiedeknecht the genus is inter- 

 mediate between the Acoenitini and Banchini. Crypturus, synony- 

 mous with Endurus Rondani, was transferred by Schmiedeknecht 

 to the Tryphoninae, where it forms his subtribe Endurina of the 

 tribe Mesoleptini. This treatment of the genus seems to us the 

 logical one. 



Leptobates Gravenhorst and Procinctus Foerster we place with the 

 Banchini; Apltanorhoptrum Foerster with the Tryphonini, where it 

 is closely allied to Stilhops Foerster, removed thence from the Ich- 

 neumonini ; and Collyria Schi0dte to the Mesoleptini, where it would 

 form a distinct subtribe. 



In biological habits and ovipositor and clypeal charactei-s, together 



with somewhat similar general form, this tribe is most closely allied 



to the Rhyssini. 



Tribe XOKIDINI. 



The tribe Xoridini of previous classifications is a very hetero- 

 geneous group. As here restricted it indues of the Holarctic fauna 

 the genera Deuieroxorides Viereck, Xorides Latreille sensu latiori 

 ( = Xylonomus Gravenhorst), and Foe/n^ma Holmgren (= CaUiclisis 

 Foerster) . 



The genera Echthrus Gravenhorst, Nyxeophilus Foerster, Helcos- 

 tizus Foerster, Xylopliruridea Viereck, (= Cryptoideus Ashmead), 

 and Xylophrurus Foerster we exclude entirely from the subfamily, 

 placing them in the Cryptinae.^ Odontomerus Gravenhorst and 

 Aplomerus Provancher are removed to form the allied tribe Odon- 

 tomerini. Helcosiizidea Rohwer, originally placed by its author in 



1 See Cushman, Proc. U. S. Nat. Mus., vol. 55, 1919, p. 536. 



