216 INSKCTA. 



ous, and composed of thirteen or fourteen joints ; the mandibles den- 

 tated on the inner side ; the maxillary palpi composed of six joints and, 

 and the labials of four. The abdomen is implanted on the thorax, 

 in several under the scutellum, and has an ovipositor usually salient 

 and formed of three filaments. 



This tribe appears to form but the single genus 



FCENUS. 



Sometimes the ovipositor is concealed, or but very slightly salient, 

 and resembles a little sting. The ligula is trifid, a character which 

 approximates these Insects to the preceding Hymenoptera. 



EvANiA, Fab. — Sphex, Lin., 



AVhere the antennae are geniculate, and the very small, compressed, 

 triangular, or ovoid abdomen, abruptly pediculated at its origin, is 

 inserted into the posterior and superior extremity of the thorax, under 

 the scutellum *. 



Pelecinus, Lat. Fab., 



"Where the abdomen, as in the following subgenus, inserted much 

 lower, a little above the orign of the posterior legs, is elongated, 

 sometimes filiform, very long and arcuated, and sometimes gradually 

 narrowed towards its base, and terminated like a club. The posterior 

 tibiae are inflated. The antennae are straight and very small f. 



Sometimes the ovipositor projects greatly, and is formed of three 

 distinct and equal threads. 



In some, the abdomen and posterior tibise are clavate ; the antennae 

 are filiform, and the ligula is entire or simply emarginated. Such 

 is Foenus proper, or 



FcENUs, Fab. — Ichneumon, Lin.\ 



The abdomen of the others is compressed, ellipsoidal, or falciform, 

 and all their tibiae are slender. The antennae are cetaceous. 



AuLACus, Jur. Spin., 

 Where the abdomen is ellipsoidal §. 



Paxyllojia, Breb., 

 Where the abdomen is falciform ||. 



In the second tribe, that of the Ichneumonides, the wings are also 

 veined, the superior ones always presenting complete or closed cells 

 in their disk. The abdomen originates between the two' posterior 



* See Fau., Jur., Lat., Gen. Crust, et Insect., Ill, p. 250. 



t See the works already quoted, aud Encyc. Method., article Pelecine. 



X See Jurine, Hymenopt. ; Lat., Gen. Cruet, et Insect., IV, 3 ; and Panzer on the 

 Hymenoptera. See also Spinol., Insect Ligur. 



§ Idem. 



II See the Nouv. Diet. d'Hist. Nat. 2d edit. ; a subgenus formed on a single spe- 

 cies closely allied to the Ophion, Fab. 



