THE CANADIAN ENTOMOLOGIST. 107 



with L. ribis, Fitch. Fitch's type has been destroyed, and there is 

 nothing left but a fragment of the twig on which the species was 

 found, showing only the original size, which must have been between 

 5 and 6 mm. in diameter. Since Fitch's short description appears to 

 agree with L. armeniacum, Mr. Pergande thinks it to be that species, or a 

 pale form of L. cerasifex, which is our most common Eastern species." 

 At the same time, Dr. Howard kindly sent me some of Prof. Cockerell's 

 L. ribis. These, together with specimens from Dr. Fletcher, P. J. 

 Parrott, and those found by me in Massachusetts, were critically studied. 



During the examination of these several lots of scales, it was 

 questioned whether some, or perhaps all, might be very near if net 

 identical with L. Kansasense, Hunter. I therefore wrote to Prof. Hunter 

 for some of his species. Without delay, he kindly forwarded one of his 

 type slide mounts, together with some scales in situ. These proved to be 

 different from the species described by Prof. Cockerell as L. ribis, 

 although in the antennae and legs there seems to be no specific difference, 

 but in the scale they differ very materially, being larger, very shiny, dark 

 chestnut brown, distinctly pitted, and the texture of the scale much 

 thicker. L. Canadense, Ckil., differs in the scale being much larger 

 than Websteri or Kansasense, smoother, not so shiny, more convex, and 

 not distinctly pitted. The antennae and legs are larger and stouter, 

 although the formula of the antennae is nearly the same. L. armeniacum, 

 Craw., is another perplexing species, which has practically seven-jointed 

 antennae, although, however, we find some individuals with only six joints, 

 with the third very long and much resembling those already cited above. 

 The scale of this species is quite large, of a pale brown colour, texture 

 very thin, crowded closely together on the twigs, minutely pitted and not 

 shiny. Lecanium Websteri, therefore, will be known by its very small 

 size: 3 mm. long, 2 broad and about 2 high, of a yellowish brown colour; 

 texture thin, not at all shiny, apparently inclined to be much shrivelled, 

 nearly hemispherical in shape and not distinctly pitted, as in L. Kansas- 

 ense, which is its most nearly related species. L. Websteri is normally 

 a six-jointed species. In no instance did I find an individual with both of 

 its antennae to have seven joints. One would be six and the other seven, 

 while it was not an uncommon occurrence to find individuals distinctly 

 six-jointed. This will also apply to L. Kansasense and L. Canadense. 

 The following measurements in micromillimeters will, it is hoped, assist 

 in the recognition of the various species cited in this paper : 



