Mr. J. O. Westwood 07i Evania, Sfc. 237 



XXXVIII. On Evania and some allied Genera of Hyme- 

 nopterous Insects. By J. O, Westwood, F.L.S. &c. 



[Read November 7, 1836, and February 1, 1841.*] 



The family Evaniadcs of Leach, or the Evaniales of Latreille, 

 comprises a group of parasitic insects of but small extent, but 

 which exhibits several very remarkable variations of structure. 



The typical genus Evania was established by Fabricius in the 

 " Systema Entomologise" in 1775, having the Sj^hex appendigaster 

 of Linnaeus as the type, but comprising, as a second species, an 

 insect of this country belonging to the genus Ceropales, observed 

 by Fabricius in the collection of Sir J. Banks. Subsequently 

 Latreille instituted another genus, which, in his early works, he 

 named Gasteruption, but Fabricius having in his " Systema Pieza- 

 torum" established the same genus under the more pleasing name 

 of Fcemis, Latreille subsequently adopted the latter name. The 

 last mentioned author also at the same time proposed another 

 genus, Pelecinus, founded upon a remarkable insect inhabiting 

 North America. Jurine added a fourth genus, Aulacus, established 

 upon an European species, and Latreille, in the " Families Natu- 

 relles" and " Regne Animal," second edit., introduced a fifth genus, 

 Paxylloma, founded upon a French species, but of which the cha- 

 racters were very slightly indicated. In addition to these, the 

 raising of one of the sections of the genus Evania into a distinct 

 genus, under the name of Brachygaster, by Dr. Leach, (and 

 under that of Hyptia by Illiger,) and the establishment of the 

 Australian genus Megahjra by myself in " Griffith's Animal King- 

 dom," comprise all that has hitherto [1836] been done relative to 

 the generic distribution of this group. 



In the " Histoire Naturelle, &'C." vol. xiii. Latreille placed this 

 family amongst the " Tripiles," between the Ichneumonidce and 

 Cynipidce, or Gallflies; but in his " Genera Crustaceorum et 

 Insectorum" he placed it at the head of the Pupophaga, imme- 

 diately preceding the Ichneimionidce, in which situation it is re- 

 tained in all his subsequent works. 



Jurine divided the Hymenoptera into three principal sections, 

 the first having the abdomen sessile, comprising the Tenthredinidce 

 and Siricidce ; the second having the abdomen pedunculate, "petiolo 

 supra thoracem infixo," containing the genera Evania, Fcenus, 



* Note. In the lists of species of the difterent genera described below, the 

 still more recent additions, up to the present time, so far as I am acquainted lliere- 

 with, have been introduced. — J. 0. IV., July 12, 1844. 

 VOL. HI. S 



