The Zoologist— January, 1868. 1051 



A A. Tail luteous or lutescent. 



a. Body brown or brownish rust-colour. 

 a. Abdomen above smooth, not tuberculate. . . .17. Tussilaginis. 

 aa. Abdomen above with tubercles in transverse series. 



* Legs black; femora luteous at the base. . . 18. Picridis. 



** Legs luteous tarsi and tips of the femora and of the tibiae black. 



19. Sonchi. 

 aa. Body deep red 20. Tanacetkola. 



1. £'. Rosce, Linn. — The apterous form is very often red. It has the 

 greatest development of the peculiar structure of the genus. 



2. S. Cyparissia, Koch. — It has not yet been noticed as British. 

 It feeds on Euphorbia cyparissias and on E. peplus. 



3. S. cerealis, Kaltenbach.— It may be the Aphis Avenae of 

 Fabricius and of Gmelin, but these authors give no description of the 

 species. It is not the A. Avenao of Schrank, and therefore that name, 

 by which I have recorded it, must give place to gran aria, Kirby, which 

 is prior to cerealis, Kaltenbach. It has been observed in North 

 America. 



4. S. Millefolii. — It frequents Anthemis tinctoria in addition to the 

 plants that I have mentioned as its food. 



5. 5. Artemisia, Fonscolombe. — Passerini observes that the descrip- 

 tion of A. Absinthii, in Ann. Nat. Hist. ii. 202, includes the true A. Ab- 

 sinthii as well as this species, which he has found on Achillea nobilis. 



6. S. Acellance, Schrank. — It differs much in structure from the other 

 Siphonophorae, and may be considered as the type of a new genus. It 

 is not generally distributed on the hazel, but sometimes occurs in 

 abundance. 



7. S. platanoides, Schrank. — The genus Drepanosiphum, Koch, to 

 which this species belongs, is very different from Siphonophora in 

 structure and inhabits, and the two genera represent two great groups 

 of Aphidinae. Drepanosiphum has no viviparous wingless form, the 

 successive annual generations are few, and it does not migrate. Four 

 species have been described, platanoides, acerina, IVlk., Tiliae, Koch, 

 and smaragdinum, Koch. D. Aceris, Koch, is a synonym of D. acerina. 

 The other group has more development of the peculiar character- 

 istics of Aphididae : the species are generally migratory, the successive 

 annual generations are more numerous, the wingless viviparous form 

 abounds, and there are more alternate generations : their migrations 

 result from the failure of their food ; they then seek new pastures to 

 maintain their existence till they resume the comparatively imper- 

 turbable security of the egg state. 



