INTRODUCTION. xHx 



wanting. Here we have a whole genus, Pezomachus, with the females 

 and often also the males apterous, which is, nevertheless, rendered distinct 

 by this very character (which obtains nowhere else) and by the distinctly 

 petiolate abdomen. The Ophioninae may become accidentally deplanate, 

 by artificial or other contingencies ; and the abdomen of the Banchini, 

 the conformation of whose areolet is peculiar to it, is naturally as much 

 depressed and sessile as is the case in many Tryphoninae.^ No reliable 

 character has yet been enunciated by which the males of the last two sub- 

 families may be discriminated, though the bodies of the former usually 

 bear more red coloration, are more fusiform and not tuberculate, with the 

 legs, excepting in the Prosopini, longer and more slender. The following 

 diagnoses are necessary to elaborate the above table : — 



Sub-family. ICHNEUMONINAE. 



Head generally transverse or tumidulous, more rarely sub-globose ; 

 eyes oblong, entire ; clypeus imperfectly discreted ; mandibles apically 

 narrowed, bi- or very rarely uni-dentate, the teeth nearly always of strongly 

 unequal length. Antennae filiform or setaceous, very rarely sub-serrated ; 

 of $ more robust and convoluted. Thorax stout, longer than high, finely 

 punctate ; metathorax profusely areated, sometimes armed with apophyses ; 

 coxal areae usually entire ; spiracles linear, more rarely sub-ovate or cir- 

 cular ; mesosternum usually without trace of lateral sulci. Abdomen 

 depressed, petiolate, oblong-fusiform or sub-linear ; first segment obtusely 

 geniculate towards its apical third, its spiracles almost always placed 

 considerably behind the centre and further from each other than from 

 apex of segment ; post-petiole generally transverse with distinct sculpture ; 

 gastrocaeli nearly always distinct ; terebra stout, concealed or only slightly 

 exserted. Legs normal or a little incrassate ; front coxae transverse, hind 

 ones not conical nor cylindrical, sometimes scopulate ; onyches very rarely 

 pectinate. Wings normal, hardly ever incomplete ; areolet nearly always 

 pentagonal, very rarely sub-deltoid or rhomboidal. 



Sub-family. CRYPTINAE. 



Head as in preceding ; eyes oblong or sub-rotund, entire or nearly so ; 

 clypeus often discreted by a distinct impressed line ; mandibles more 

 rarely narrowed apically, bi-dentate, teeth generally of equal length. An- 

 tennae setaceous, often very slender or incrassate throughout. Thorax 

 stout, finely punctate ; mesonotal notauli distinct ; metathorax often im- 

 perfectly areated, sometimes with large apophyses ; spiracles sub-circular, 

 more rarely ovate ; mesosternum always with distinct lateral sulci. Ab- 

 domen usually distinctly petiolate, rarely sub-sessile and sub-compressed ; 

 first segment arcuate, longer than width of the generally smooth and 

 glabrous post-petiole, its spiracles in or behind the centre and nearer to 

 each other than to apex of segment ; gastrocaeli wanting or sub-obsolete ; 

 terebra exserted, often longer than half the abdomen, very rarely sub- 

 concealed. Legs slender, sometimes with femora incrassate, or tibiae 

 intumescent. Wings rather ample, not rarely rudimentary or wanting ; 

 areolet pentagonal, sometimes imperfect, rarely wanting, often very large 

 and equilateral. 



1 To such an extent is this the case that Professor Thomson considers them to form a natural 

 group in the latter sub-family ; see my notes on this group, E.M.M., 1903. 



