i6 



ENTOMOLOGICAL NEWS. 



[Jan., '10 



tive lengths of the base and filament of antennal segment VI 

 in the two species is quite distinct as is shown by the following 



average measurements : 



Further, there are no dark abdominal markings on the dor- 

 sum of the wingless females of negundinis, these markings 

 being prominent, though variable, characters in aceris. 



The dimorphic forms, of the two species under discussion, 

 although having a remarkable resemblance, are likewise quite 

 distinct. The dorsal "plates" are very different as is shown 

 in figures I and 2. The leaf-like flabellae on aceris are 

 usually rounded while those on negundinis in most cases at 

 least, are more or less pointed. Another very prominent dif- 

 ference is the relative lengths of the base and filament of the 

 last antennal segment (IV) as is shown in the following table 

 and in figures 3, 4, 5 and 6 : 



We have in America a Chait-ophorus on the Norway and 

 hard maples, which is very closely related to the European 

 aceris, but which appears to be distinct probably a variety of 

 aceris. The writer wishes, however, to study the species 

 throughout the year in its various forms before making any 

 definite statements. 



