BRITISH ICHNEUMONS. 



Tribe 

 PLECTISCIDES. 



This Tribe is recognised from tlie remainder of the Ophioninae by 

 having the stigma short and not narrow, the radial cell short and not 

 narrow, with the areolar angle of the radius somewhat acute, though 

 much less so than in the Porizonides ; the hind legs not stout and dentate, 

 as in the Pristomerides; the cubital ncrvure of the hind wing distinct, 

 and not obsolete as in the Porizonides; and the head is nearly always 

 small with clypeus distinctly convex and generally laterally compressed, 

 not deplanate as in the Cremastides. 



In general the head small and usually distinctly constricted posteriorly 

 with a strong transcarina between vertex and occiput; eyes not internally 

 emarginate, rarely pubescent; frons not strongly punctate, usually smooth ; 

 face parallel-sided, rarely apically contricted, very rarely centrally promi- 

 nent below scrobes; clypeus always strongly discreted and invariably 

 strongly convex with its sides generally compressed ; cheeks very 

 rarely elongate, often sulcate ; mandibles weak, apically attenuate 

 with teeth unequal and sometimes obsolete ; palpi elongate and 

 slender. Antennae with seventeen to forty joints, the flagellum fili- 

 form and pubescent, often very slender; scrobes indistinct or want- 

 ing; scape usually subcircular or bulbiform and deeply incised. 

 Thorax high and subcompressed, with notauli often distinct but sternauli 

 obsolete or wanting ; metathoracic areae variable in extent, but very 

 rarely complete, areola not infrequently ill-defined, costulae hardly ever 

 present, basal carina of petiolar area nearly always strong and sometimes 

 with apophyses, but occasionally all metathoracic costae wanting ; spira- 

 cles small and circular; pleurae glabrous and nitidulous, very rarely 

 sculptured. Scutellum normal, rarely apically compressed. Abdomen 

 of variable shape; basal segment usually linear, rarely apically explanate, 

 and rarely distinctly petiolate basally, with spiracles subcentral and discal 

 carinae unusual ; second not transversely impressed, though often with 

 strong thyridii ; anus generally in 9 laterally a little compressed ; terebra 

 variable in length, as long as body or hardly extending beyond anus, 

 usually about half length of abdomen. Legs usually slender, with coxae 

 elongate, hind tibiae a little incrassate and sometimes either constricted 

 or apically emarginate; calcaria short and slender, the tarsi also always 

 slender with claws simple, not pectinate, rarely large and curved. Wings 

 not small; areolet (i) transversely oblique and distinctly petiolate, (2) 

 with its inner nervure, called the areolar, distinct and the outer wanting, 

 as in Hemiteles, or (3) so utterly wanting that even the inner nervure is 

 obliterated by "radius cum cubito connivens," as Haliday aptly says; 

 basal nervure usually continuous, brachial cell small, lower angle of 

 discoidal usually acute; cubital nervure of lower wing distinct to base 

 and usually strongly curved before the nervellus, which may be straight 

 or geniculate. 



The relation of the Plectiscides to the species treated of at the end of 

 the last volume (Ichn. Brit. iv. 315) is so close that Thomson places the 

 genus Adtiogna/hus under the present Tribe, from which I consider it 

 sufficiently distinct, both in its structure and Tenthredinid hosts. Schmie- 

 deknecht speaks of Ashmead's reference of this Tribe to the Ophioninae 

 in 1900 as some new thing; to us it has never stood elsewhere, for 



