282 THE CANADIAN ENTOMOLOGIST 



Now specimens of populea from Europe agree exactly in 

 measurements, etc., with American specimens, excepting that the 

 unguis of segment VI is very slightly longer. Moreover, the ex- 

 amples of both species have a much more cylindrical cornicle than 

 have the specimens of popiilifolicB. The writer is therefore con- 

 sidering these American specimens to be populea. The European 

 examples have segment \T usually about (0.128 mm. 4-0.17 mm.). 



In regard to pilosa Buckton, the writer has never had an 

 opportunity to study forms supposed to be this species. From the 

 description given by Buckton, it would seem very much as if he 

 had two species before him. His apterous forms would very well 

 agree with populea, whereas his alate form seems to be populifolice, 

 or a species near it. This will be seen from the measurements he 

 gives for the cornicles in the two forms. Since Pergande, who had 

 seen the type, placed pilosa as perhaps the same as his populea, 

 this would also tend to indicate that Buckton's alate form is 

 populifolice Fitch. 



Pterocomma beulahensis (Ckll.). 



The measurements given for this species by Cockerell would 

 make it very difficult to include it under populea. It has, however, 

 the cornicles about ecjual in length to the hind tarsi. The type 

 Slide of the species is now in the National Museum collection, 

 and on it are mounted four alate specimens. These show some 

 variation in the sixth antennal segment. One antenna measures 

 for (0.176 mm. + 0.336 mm.), and one (0.16 mm. + 0.32 mm.). 

 It will be seen that this proportion is very different from that of 

 populea. A more prominent character, however, is met with in 

 the beak. In all our specimens of populea the beak is long, 

 reaching beyond the hind coxa?, sometimes even to the base 

 of the cornicles, or very near them. The beak in beulahensis is 

 much shorter, extending hardly to the hind coxae, sometimes not 

 reaching them. The cornicles are somewhat swollen, a character 

 which is not so evident in populea. Moreover, beulahensis is more 

 elongate, having the general look of populifolice, whereas populea 

 has a shorter, "bulkier" appearance. 



