PARASITIC HYMENOPTERA. 481 



limits of tlie genera, has produced an arrangement which 

 seems less simple and natural. Of the genera, seven^ had 

 been previously established (but not all equally well defined) 

 by Fabricius, Latreille, Schranck, and Jurine; the rest we 

 owe to the labours of the same accomplished naturahst, who 

 has besides described at length a considerable number of the 

 European species ; of which, also, several will be found 

 dispersed among the Fabrician genera, and more collected 

 and arranged in the Ligurian Fauna of Spinola. Seven 

 species only are noticed by Linne ; two of which are placed 

 among his Ichneiimones majores, four with the minuti, and 

 one is appended to the genus Cynijis. The little that is 

 known of their instincts and economy is to be sought in the 

 pages of Reaumur, and of the incomparable Swede, in patient 

 observation almost his equal, and in his systematic views (may 

 I not say) unrivalled among his contemporaries. A few of the 

 more familiar species have also been figured, and their habits 

 noticed, by some of the older writers upon insects, as Madame 

 Merian, Frisch, &c. ; and some interesting contributions to 

 their history, in recent publications, are to be consulted under 

 their respective heads. 



As the general form is similar throughout the family, the 

 second chapter of Gravenhorst's Prolegomena may be referred 

 to for an elaborate account of the external anatomy. I shall 

 merely allude to some characters which pervade the present 

 branch, reserving the consideration of other distinctions for 

 the minor groups to which they are confined. In general it 

 may be remarked, that these exhibit greater variety in the 

 details than exist among the proper Ichneumones : the defined 

 white or yellow markings there so prevalent are wanting here ; 

 the white ring of the antennce is also excluded from the cha- 

 racters of the group, by Von Essenbeck ; but I am acquainted 

 with one instance where the female has such a distinction.^ 

 In the upper wings the exterior areolet of the disk is always 

 open, the anterior is mostly complete, which is never the case 

 in the others ; the cubital area is usually of more uniform 

 breadth, and the second areolet of moderate or ample dimen- 

 sions ; sometimes that area is contracted in the middle, and 



* Agathis, Bracon, Sigalphus ( Sphceropyx), Microgaster, Cheloniis, Incuhus 

 (Aphidius), Altjsia. 

 Rogas dispar. Hal. 

 NO. V. VOL. I. 3 Q 



