272 Mr. J. O. Westwood on Evania and 



number in the joints of the antennae is one of the most ordinary 

 of the anomalies which those organs exhibit. 



On more minutely examining the insect we find, however, that 

 an equally strong relation with the Pupivora is possessed by it, 

 founded upon other characters, in addition to that of the antennae, 

 which in their multi-articulate structure are represented by those 

 of various Tetithredinidce, and more especially by the Ichneu- 

 monidce. 



The structure of the trochanters, and the irregularity in the 

 number of the joints of the palpi, (6 and 3 instead of 6 and 4,) 

 joined to the number of segments in the abdomen, of which there 

 are only 5 (instead of 6 or 7, as in the sexes of the aculeate 

 Hytnenoptera), are reasons which appear sufficient to warrant us 

 in placing the genus amongst the aberrant Hymenoptera, amongst 

 which we will now inquire its place. 



The nonsessile abdomen at once removes the genus from the 

 Tenthred'midc^, whilst the veining of the wings, the comparative 

 fewness of the joints of the antennae, and the 6-jointed maxillary 

 palpi, remove it from the Ichneumones genidni. We must there- 

 fore refer it either to the adscitous Ichneumonidce or to the Eva- 

 n'lidce, which are the only other families to which it can be con- 

 sidered as allied, [t is amongst the Alysudcs, and especially in 

 Alys'm, that we find the most complete veining of the wings 

 imited with very strong and dentate mandibles, and 6-jointed 

 maxillary palpi ; but no adscitous Ichneumon possesses two recur- 

 rent veins, nor has the costal areolet distinct. Now these two 

 characters, which with the broad toothed mandibles we have found 

 to be so characteristic of the Evaiiiidce, are found in this genus ; 

 moreover, in Evania we have the minute labrum, strong toothed 

 mandibles, 6-jointed maxillary palpi, irregular shaped labial palpi, 

 bifid ungues, and elongated anterior trochanters of Trigonalys. 

 Fcenus also presents us with the minute labrum, strongly toothed 

 mandibles, and 6-jointed palpi ; whilst by minutely examining the 

 direction of the cubital vein of Aulacxis we find evidence of the 

 obsolete existence of a transverse cubital vein, which, were it 

 present, would render the fore wings of the two genera absolutely 

 identical, although the hind wings are, it is true, very differently 

 veined ; nevertheless, if the veins be traced, they will be found 

 nearly to correspond with those of the hind wing of Trigonalys. 

 We thus learn that the fewness of the joints of the antennae, 

 as well as the mode of insertion of the abdomen, are no longer 

 characteristic of the group or family typified by Evania. 



The genus is named in allusion to the triangular form of the 



