24)0 (March, 1887. 



superior lateral 12 — 13, inferior lateral 13 — 14. The margin has two median trilobed 

 lobes ; on each side some small emarginations, and beyond, as far as the preceding 

 segments, 9 — 10 spines." In our species the number of spinnerets is much less, the 

 median lobes are not trilobed, and the marginal spines are certainly not 9 — 10, only 

 two or three. 



Comstock described his Diaspis osfreceformis from materials re- 

 ceived from Dr. Signoret, and therefore it is the same as Dr. Signoret's. 



Goethe's Diaspis ostreceformis appears, on the whole, to be the 

 Aspidiotus ostreceformis of Curtis, for he says : — " I observe that the 

 scales of the (J are not essentially different from those of the $ ;" 

 therefore, they are not those of a Diaspis. He makes out 9 joints in 

 the antennae of the ^ , but, as before stated, this may only be a matter 

 of observation. The doubt about the identity of his species with that 

 of Curtis arises from his statement of the number of spinnerets in the 

 respective groups being — " middle 10 — 12, upper lateral 12 — -13, lower 

 lateral 13 — 14," — being the same as given by Signoret for his species, 

 but not the same as found in ours. Mr. G. S. Saunders prepared a 

 number of specimens that I had collected from plum, apple, pear and 

 cherry trees ; he found they all exhibited exactly the same characters, 

 and the number of spinnerets, &c., to be as I have stated above. 



About the middle of March last I noticed that the trunk of a 

 plum tree had on the bark numerous white spots about a millimetre 

 in diameter, and on examination I saw that they were the ventral skins 

 of old scales of an Aspidiotus that had fallen off and left these affixed. 

 Looking more closely I saw other scales of a previous generation still 

 remaining, but they were loose and came off with a touch ; and there 

 were also numerous recent scales adjacent, either in batches or single, 

 tightly adherent. Other scales of the same sort were abundant on 

 apple, pear and cherry trees. From some that I removed, still attached 

 to pieces of the bark, and put into gauze-covered glasses indoors, I 

 obtained a few males early in May. My description, made at the 

 time, agreed so closely with that of Curtis's Aspidiotus ostreceformis, 

 that I quite believed I had found that species ; but there was just 

 room for a doubt, because, although I diligently searched, I could not 

 detect the "very small, white, carinated scale" which Signoret attri- 

 butes to the $ of this species, and which gives the character of Diaspis. 

 However, I eventually came to the conclusion that Signoret's species 

 was not the same as that of Curtis, as he had deemed ; but in order to 

 elucidate the matter, I sent some examples to Pi'ofessor Comstock, of 

 Cornell University, Ithaca, New York, the State Entomologist, than 

 whom no one has had greater experience in the examination of Diaspina, 

 and he having very kindly devoted a considerable attention to them, 

 writes thus : — 



