208 ENTOMOLOGICAL SOCIETY 



Figs, i, 2, and 3 represent the head of three different Bracon- 

 ids. The first is quadrate, with head behind eyes very long ; 

 the second is transverse-quadrate, the head behind eyes not nar 

 rowed ; the third is also transverse, but with head convergent 

 behind eyes. 



Now, strange to say, all three forms, with some others, are 

 still retained to-day in the genus Bracon, according to the present 

 classification in vogue, and they will illustrate what I mean when 

 I say the head and appendages, for use in classification, are still 

 unexhausted. In my recent studies in the Braconidae, these dif 

 ferent shapes at once attracted my attention, and I soon found 

 they were correlated with other characters, which will enable a 

 subdivision of this extensive genus into half a dozen or more new 

 genera the other characters being found in the antennae, shape 

 of scape, in the palpi, and in the thorax and abdomen. 



Figs. 4 and 5 represent two forms of head in the family Kva- 

 niidae, while figs. 6 and 7 represent two characteristic forms to 

 be found in the Chalcididae, belonging to the subfamily Pteroma- 

 linas, as seen from in front, all the others having been shown 

 from above. 



In this last family not enough attention has been given, in de 

 scriptive work, to the shape of the head as seen from in front, 

 and to the shape of the clypeus, shape of eyes, mandibles, the 

 character of the maxillary and labial palpi, and to the insertion 

 of the antennae. 



In fig. 6 the head, as seen from in front, is nearly round, 

 slightly wider than long, the clypeus being bidentate, the anten 

 nas being inserted on the middle of the face ; in fig. 7 it is 

 oblong, nearly twice as long as wide, the clypeus being truncate, 

 while the antennae are inserted just above the clypeus or the 

 mouth. 



I would call special attention here to the great difference ob 

 servable in the clypeus and to its importance in classification. 

 Sometimes it is entirely separated from the face by grooved lines, 

 or separated only at the sides or not at all, as shown in fig. 6. 

 Its anterior margin may be unidentate, bidentate, tridentate, 

 truncate, rounded or emarginated, and these differences should 

 always be mentioned in descriptive work. 



