80 PROC. ENT. SOC. WASH., VOL. 20, NO. 4, APR., 1918 



In a previous paper the writer had considered this group of 

 family rank but after studying the larvae and habits it seems that 

 the group is so closely allied with certain subfamilies in the 

 Tenthredinidae that it should be treated as a subfamily. More- 

 over, the differences between the Diprionids and the Tenthre- 

 dinids is not of as much taxonomic value as the differences be- 

 tween the Tenthredinids and Argids or Cimbicids. The writer, 

 therefore, prefers to consider the group as a subfamily of the 

 Tenthredinidae where it can easily be separated from the other 

 groups by the multi-jointed antennae and well defined dorsal plate 

 of the mesoepimeron. The difference between Diprion and 

 Monoctenus is not, in the author's opinion, great enough to be of 

 subfamily importance. The length of the fusing of the sub- 

 medius and anal veins varies and in many of the wings of species 

 of Monoctenus there is a distinct contraction in the first anal 

 cell. In fact the anal cell in certain individuals of the subfamily 

 differs so much that if this was the only character they would be 

 placed in different subfamilies from their brothers and sisters. 

 A full discussion of the variation of the anal cell and vein has 

 been prepared but for this paper it is sufficient to say that while 

 for most species and specimens it is constant there are some 

 specimens in which the basal abscissa of the anal vein is nearly 

 straight; and there are also specimens in which the interanal is 

 wanting. 



'If the Erlangen List of Panzer 1801 is treated as a publication 

 validating the new names there proposed the genus Diprion 

 Schrank will fall as a synonym of the older name Pteronus Panzer 

 (or Jurine?) and the subfamily name should be changed to 

 Pteroninae. For the time being the writer prefers to leave this 

 matter open, but he admits that as far as he can see there is no 

 rule of the Internation Commission which would even suggest 

 that this upsetting, long overlooked, review of an unpublished 

 book cannot be used for the establishment of certain generic 

 names. 



The five genera which belong to this subfamily may be dis- 

 tinguished by the following key: 



Key to Genera based on Adults. 



1. First and second anal cells separated by the fusing of submedius 

 and anal veins; antenna of male uniramose, of female serrated; 

 malar space large; longer calcarium of hind tibiae shorter than 



basitarsus; claws with an inner tooth 2 



First and second anal cells normally separated by the intcranal 

 vein, but occasionally this is wanting and the two cells are con- 

 fluent; antenna of male biramose, of female usually serrate but 

 sometimes shortly biramose 3 



