180 [August, 



It will be seen on comparingtheabove with the descriptions given 

 by previous writers that there are some slight discrepancies as to the 

 colour of the scale, and the presence or absence of grouped spinnerets. 

 "Grey," "dark grey" (schwarzgrau), is given as the colour of the 

 scale by Schrank and Low respectively ; but I attach very little im- 

 portance to this, so slight a difference in colour stands for very little ; 

 but the presence or absence of grouped spinnerets is very important. 

 So far as I can ascertain, it is the immature $ that is without the 

 spinnerets, and that very probably these latter are not developed until 

 the period of gestation, but I am not at all certain of this. It can 

 only be proved by an examination of the living insects in their suc- 

 cessive stages of development. 



Low (Z. c.) found no grouped spinnerets, and says there are only 

 two pairs of lobes. Quite half of my specimens are loithout grouped 

 spinnerets, and the third lobe, which is very small, might easily have 

 been overlooked. . The rest of his description agrees so well that I 

 have no doubt as to the identity of the species. 



This species runs Prof. Comstock's Aspidiotus ? pini (Rep., 1880, 

 p. 306) very close. Externally there is no difference ; and the mar- 

 ginal fringe of both is almost identical. It is only by the number 

 and arrangement of the grouped spinnerets that they can be separated. 

 Some forty specimens of A. pini, Comst., which I examined are also 

 without grouped spinnerets, which is very singular. Nothing is said 

 of this in Prof. Comstock's description. I imagine, therefore, the 

 absence was overlooked by him. 



We have all been attaching very great importance to the presence 

 or absence of spinnerets in the separation of species, and, I think, 

 rightly ; but I am absolutely certain that in this species both forms 

 occur in the same colony, on the same food-plant, and at the same 

 time ; and that there is no external character by which they can be 

 separated. 



Mr. Cockerell (Canad. Ent., 1894^, p. 180) says that he has found 

 the same variation in Asp. destructor, Sign., but I believe not in the 

 same colony of insects, or under the other conditions stated above. 

 In this case, therefore, the doubt still remains. 



Hah. : near Prague, Bohemia, on Pinus sylvestris. Received 

 from Herr Karel Sulc, May, 1894. 



As to the synonymy of the species, I have had to fall back on 

 Mr. J. W. Douglas for his valued help and translations, for which I 

 am very greatly indebted to him. 



