38 GENERA OF HYMENOPTERA. 



base, and the tliird receiving the second recurrent, wliicli is straight, 

 a little in front of middle ; posterior \ving> well veined ; legs moder- 

 atelv short, slender, the four posterior til)i:e each witli two a])ical 

 spui-s, all the tarsi o-jointed, their claws l)ilid ; abdomen attached to 

 the apex of the metathorax, subsessile, short, ovate, convex, narrowed 

 and suddenly depressed at base, the apex deilexed, especially in % , 

 the second segment much the largest ; beneath, the large second seg- 

 ment of the % is more or less strongly produced at the apical middle. 



Of this anomalous genus four species have been described as oc- 

 curring in our fauna. They are widely disti'ibuted and rare, the 

 localities beiug ^la.>sachusetts. West N'irginia, Xorth Carolina and 

 Nevada. 



Lycogaster Shuck., appears to be nothing more than the % of 

 Tricjonalijs. 



Family ICHNEUMONIDiE. 



This very extensive family (the Ichneumones genuini Grav.) is dis- 

 tingui.'shed by the well-veined anterior wungs (fig. 9, which are rarely 

 i-udiineiitary i>r wanting as in Pezomachus and allied genera) having 

 the nervure separating the first submarginal cell from the first dis- 

 coidal cell either entirely obliterated or else reduced to a mere stump 

 of a vein (ij, whereby the two cells, termed the cubito-discoidal cell 

 (■)), become confluent; moreover, the second submarginal cell, or 

 areolet (6), is greatly reduced in size, sometimes petiolate and often 

 entirely obsolete; the third discoidal cell (9) is always complete 



F'g- 9- — Anterior wing of A/i/ieuii/o/i. 



1, median or externo-niedial cull ; 2, subniedian or inlerno-nudial cell ; 3, anal cell ; 4, 

 inarninal or radial cell ; 5, cubito-discoidal cell ; 6, areolet or second submarginal cell ; 7, 

 third submarKinal cell; 8, second discoidal cell; 9, third discoidal cell; 10, first apical 

 cell; II, second apical cell ; a, costal and subcostal nervures blended ; b, externo-medial 

 nervure ; c, anal nervure; d, basal nervure: e, marginal or radial nervure; f, first trans- 

 verse cubital nervure; g, second transverse cubital nervure; h, transverse medial ner- 

 vure; >, abbreviated cubital nervure or "stump of a vein"; j, discoitlal nervure; k, 

 cubital nervure ; 1, recurrent nervures : m, subdiscoidal nervure ; n, stigma. 



J 



