The present version simplifies the previous versions, in particular 
Cratichneumon s.l. is shared in genera s.s., 
But the difficulty using the couplet 
18 remains
------------------------- The works of 
Berthoumieu, 
Constantineanu, 
Schmiedeknecht & 
Valemberg 1983 are quoted in  
viewtopic.php?f=11&t=47260- It is necessary to add :
Hilpert 1992 : in "Entomofauna - supplement 6", Zur Systematic der Gattung Ichneumon ... - 389 p.
Riedel 2012 : in "Linzer Biologische Beiträge", Revision ... Coelichneumon ... - p.1477/1611
Valemberg 2010 : in "Bull. SE du N. de la France", ... Genera Ichneumonologica ... Ichneumoninae
----------------
Terminology see 
viewtopic.php?f=11&t=47025----------------
An OXYPYGI is characterized in :  
viewtopic.php?f=11&t=47043-------------
In this last key, the genera s.l. are the ones quoted exclusively by 
Constantineanu.
For this author, a number of synonymic species (for 
Taxapad) are  placed in different genera (often 
Cratichneumon) !
I took into account it in my key (although this does not appear explicitly).
--------
In the OXYPYGI, I ignored 
Hoplismenus and some species of other genera (today in PLATYURI).
---
Contents of genera (sensu 
Constantineanu) quoted in my key  : genera (sensu 
Taxapad)
Coelichneumon s.l. : Aglaojoppa 
centummaculata - Coelichneumon s.s. - some Ichneumon ? - Syspasis 
lineatorExephanes s.l. : Diphyus 
macilentus - Exephanes s.s. - 
? Vulgichneumon 
clypeatus Ichneumon s.l. : Ichneumon s.s. (pars) - Syspasis 
haesitator - etc
Protichneumon s.l. :  Amblyjoppa 
fuscipennis, 
proteus - some Ichneumon ? - Lymantrichneumon 
disparis - Paracoelichneumon 
rubens - Protichneumon s.s.
Stenichneumon s.l. :  Aoplus (pars) - some Ichneumon ? - Orgichneumon 
calcatorius - Platylabops 
apricus, 
speciosus - Stenichneumon s.s. - Syspasis (excluded 
haesitator, 
lineator) - Ulesta 
perspicua--------------
In the next 1 or 2 messages, I hope to give the keys of the genera containing only few species.
If I can finalize the keys for other genera, they will be the object of future messages.
However the 
Ichneumons s.s. & 
Coelichneumons s.s. will not be treated, it will be necessary to you refer to the works of 
Hilpert & 
Riedel quoted at the beginning of this message.
-------------
Before the key itself,  I add the photos of 3 OXYPYGI ♀ .
-----------------------------------------keywords :
Hymenoptera Ichneumonoidea Ichneumonidae Ichneumonini Oxypygi Aoplus Baranisobas Barichneumon Chasmias Coelichneumon Cratichneumon Crypteffigies Crytea Ctenochares bicolorus Deuterolabops eupitheciae Eupalamus Exephanes Gareila Heresiarches eudoxius Homotherus Ichneumon Melanichneumon Platylabops Protichneumon Rhysaspis rugosus Rictichneumon Rubicondiella externata Rugosculpta gemmela Stenichneumon Stenobarichneumon Vulgichneumon