CHAITOPHORUS BETUL^. 139 



dense masses near London on tlie twigs of the willow, 

 "and that eacli row overlaps the other below it." It 

 feeds also on the Lombardy poplar, Poiniliis dilatafa, 

 from which tree Prof. Trail forwarded me specimens 

 from Aberdeen towards the middle of September. 

 Amongst these were small red individuals which I 

 think are probably apterous males. 



The figure given by Koch must be considered to bo a 

 very rough one. It very poorly represents the Scotch 

 insects which I take to be Aphis poimlea of Kaltenbach. 

 Koch says, in his diagnosis of the genus Cladobius, that 

 the seventh antennal joint is very small. Passerini points 

 out, and I agree, that it never is smaller than the sixth, 

 and mostly exceeds it. Passerini further thinks that 

 Koch's figures and characters point more to a Lachnus, 

 and, indeed, that they suggest L. jnmctatus, Burm. The 

 former biologist notices that the oviparous females 

 separate in autumn from the rest of the colony, and in 

 all cases under his observation deposited about the 

 buds, and at the points of the branches, four dirty 

 yellow eggs, which afterwards became black. 



Chaitophorus BETULiE, BucJctoii. Plate LXXXII, figs. 



1, 2. 



Apterous viviijarous female. 



Inch. Millimetres. 



Size of body 0*045 X 0-022 1-13 X 0-55. 



Length of antennaB 0*035 0*88. 



„ cornicles wartlike. 



In the month of September Mr. Wallace forwarded 

 me certain Aphides, which, as they did not tally with 

 any recognised descriptions, I have thought it best to 

 separate from others, although I had no advantage 

 of an examination of the corresponding winged 

 forms. The apterous female is dark olive, hirsute, 

 and tuberculate. Head broad, with four occipital 



