214 ENTOMOLOGICAL SOCIETY 



In figs, i to 12, on Plate VI, I illustrate a few of these types. 

 Figs, i and 2 represent two typical forms of the front wings 

 found among the Braconidae. Here, you will notice, the stigma 

 in one is greatly thickened ; in the other it is long and slender, 

 although otherwise there is a close resemblance between the two. 

 On a closer inspection, however, we will see there are marked 

 differences. In fig. i the submedian cell (2) is not longer than 

 the median (i), while in fig. 2 this same cell is longer than the 

 median. 



Another difference is in the recurrent-nervure (1). In one it 

 enters the first submarginal cell ; in the other it is received by the 

 second submarginal cell. There are also other differences. In 

 fig. i the discoidal nervure (j) is straight; in fig. 2 it is angu 

 larly broken ; still another great difference is in the radial cell, 

 the one being much smaller or shorter than the other, the radius 

 in one not extending to the apex of the wing. These slight dif 

 ferences-are of the greatest importance in a study of these insects. 



Fig. 3 represents the typical hind wing of a Braconid, while 

 figs. 4 and 5 represent hind wings of Ichneumonids. Fig. 6 rep 

 resents the hind wing of the peculiar and rare genus Rhopa- 

 losoma, still classed with the Braconidas. Observe what a marked 

 difference there is between these forms, and what admirable char 

 acters they present for classificatory purposes ! Why is it that 

 American students have made no use of these excellent charac 

 ters found in the venation of the hind wings of these insects? 



Is it not time for us to begin to make use of them in our tables ? 



THE ABDOMEN. 



In the third division of an insect, or in the abdomen, may be 

 found a host of most excellent and valuable characters for use in 

 systematic work. These lie in its shape, the felative length of 

 the segments the tergites and sternites, and in the position of 

 the spiracles. 



The value of these I will attempt to show by the use of the 

 few rough figures on Plate VII. 



In the family Braconidae we have an extensive subfamily, 

 termed the Microgasterince, comprising an excessively large 

 number of minute species of great economic importance, as all, 



