1998 Thr Zoologist— February, 1870. 



the male nor into the ovipavDiis feniule, and therefuve ihey cannot be considered as 

 true species. Many volumes might be written on the migrations and settlements and 

 consequent variations that occur. 



A. Hederce (S. S. 1298).— Kallenbach, who first characterized A. Hederae and 

 A. Ilicis, suggests that they may be varieties of one species, and I have been unable 

 to detect any permanent diflference between them, and accordingly consider them as 

 one species. I have tied a twig of ivy covered with Aphides to a shoot of holly: the 

 Aphides crawled from the ivy to the holly; they did not feed there, and soon passed 

 away. This might be expected, for the apterous form of Aphis, as the genus is now 

 restricted, never moves from ihe spot where it feeds until its food withers, and then it 

 perishes. The winged form hardly feeds after it migrates. 



A. Sambuci (S. S. 1298).— Passerini cites this species as the lype of the genus 

 Aphis as it is restricted by him. Some of the species which he ennmeraies should be 

 excluded from it, and it comprises very numerous closely -allied species, or, it may be, 

 forms whose respective differences are occasioned by their food. The ovipusition of 

 A. Sambuci has not yet been observed. It is especially remarkable on account of the 

 suddenness of its appearance on the elder, and on account of its rapid increase. Its 

 profusion in 1(^09 exceeded that of every preceding year in which I have observed it. 

 It sometimes occurs with a pale green hue, very convex, and with nectaries not 

 more than li;ilf the usual length. Two variations of its structure are here briefly 

 meiitioiied. First. — Oval, bluish green. .Antennae less than half the length of the 

 budy. Nectaries comparatively short. Legs rather short. Second. — Triangular, 

 widening from the head to the tip of the abdomen, which is almost truncated. The 

 larva of an Agromyza sometimes devours A. Sambuci, and may be the same species 

 that is much more destructive to A. Symphiti. 



A. Laburni (S. S. 1298). — It generally looks very different from A. Rumicis, but 

 the gradations of size and colour in the dark-coloured individuals of this genus are 

 very numerous. In 1869 it appeared in excessive numbers. Apterous female. — 

 Black, uniformly covered with while tomentum. Antennae white, black at the base 

 and towards the tips. Nectaries about twice the length of the tail. Legs white; 

 femoia black, white at the base; tarsi and tips of tibiae black. 



A. Papaveris (S. S. 1298). — A distinct difference should have a definite name, 

 whether it be termed a species or a variety, but there is no determinate difference 

 between A. Papaveris and A. Rumicis, and I believe that many so-called species and 

 A. Rumicis will he found to have a common annual origin. 



A. Rumicis (S. S. 1298). — An Aphis that occurs on the Guelder rose (Viburnum 

 Opiilus), in July, is quite distinct from A. Viburni and may be referred to this species, 

 and the following description refers to the apterous female : — Dark green; disk rather 

 paler. Antennte while, more than half the length of the body, black at the base and 

 for half the length from the tips. Nectaries a little longer ihan the tail, about one- 

 tenth of ihe length of the body. Legs while; femora except the base, tarsi and tips 

 of til)iiE black. Length J line. 



The following description refers to an Aphis that feeds on the leaves of the 

 vegetable marrow, and is probably a variety of A. Rumicis: — July. Apterous ovi- 

 parous female. — Oval, dull, rather dark green, mottled with paler green, one-third of 

 a line in length. Antenute pale green, a little more than half the length of the body. 

 Nectaries black, about one-sixth of the body. Tail short. Legs pale green, rather 



