THE CANADIAN ENTOMOLOGIST 285 



there is little difference in proportions. The Ontario material 

 collected on the Karwatha Lakes is uniformly different from this, 

 averaging as previously given (0.16 mm. +0.352 mm.). One 

 specimen had the measurements (0.16 mm. +0.384 mm.) and one 

 (0.176 mm. +0.352 mm.). These measurements agree in proportion 

 with those given by Oestlund, and the writer, therefore, prefers to 

 hold bicolor as distinct on this basis until large collections can be 

 made and studied. 



In regard to the species flocculosa Weed, smithice Mon., and 

 salicti Harris, no remarks will here be made, since these species 

 are fully dealt with by Wilson, and the writer has examined some 

 of Weed's specimens, but a species described by Patch (1913) as 

 antennatum should be mentioned. It cannot be definitely described 

 in full until alate forms have been found. Another species has 

 been described asfarinosus by Del Guercio (1913). In this species 

 the cornicles are cylindrical, but very much longer proportionately 

 than those of populea. 



Pterocomma steinheili (Mordwilko) 



A third species, not mentioned by Wilson, is one named 

 steinheili by Mordwilko. Through the kindness of Mr. J. J. Davis, 

 I have been able to examine a slide of specimens received by him 

 from Mordwilko. One alate form artd several apterous ones are 

 present. The species is very close indeed to beulahensis Ckll., and 

 it is the writer's belief that the two are identical. There is one 

 marked difference, however, between the alate specimen of 

 steinheili and those of beulahensis. The lateral tubercles of the 

 abdomen of steinheili are nearly twice the size of those of beula- 

 hensis. It is quite probable that this is a variable character and 

 that the two species cannot be separated by means of it. Since, 

 however, only one specimen of the alate form of steinheili is avail- 

 able for study, it is necessary on this basis to keep them distinct. 



Measurements of the alate viviparous female: Antenna? Ill, 

 0.432 mm.; IV, 0.288 mm.; V, 0.32 mm.; VI (0.16 mm + 0.272 

 mm.). Cornicle, 0.256 mm.; hind tarsus, 0.224 mm. 



