PHYLLOXERIDJ!. 69 



sizes, enclosing males and females, are laid by an 

 apterous individual. 



The last of these species feeding on the oaks is 

 Phylloxera acanthochermes : and it partakes also of the 

 above anomaly of showing the pupiferous form wing- 

 less. I can say very little more of this curious Aphis 

 than what Kollar has told us. It is surrounded in its 

 gemmans period with star-shaped appendages, which, 

 remind one of the coccido us mealy-bugs (Dactyl opius). 

 I have had only one opportunity of examining it at 

 Bordeaux, and then I chanced to obtain the apterous 

 Pseudogynoe pupiferce, which produced pupge, out of 

 which I obtained males and females. The first life- 

 stages of this insect are unknown. 



There yet remains for description the dreadful 

 nuisance of our vineyards, Phylloxera vastatrix. It is, 

 however, so well known that I can hardly add any new 

 facts to the very complete information given by my 

 excellent friend Riley in his interesting Reports from 

 1869 up to this day. 



Introduced into Europe about twenty years ago, it 

 has in its struggle for life destroyed the best vineyards 

 of the Continent. Professor West wood, the " actual 

 prince of Entomology" (as we used to call Latreille), 

 has described the gall-making form (fundatrix) under 

 the name of Peritymbia vitisana, a name well adapted 

 to the habits of the foundress whilst surrounding her- 

 self with the gall in which she must die. If, for the 

 scientific world, sub-genera are to be created for the 

 grape-louse, this species should be called Peritymbia 

 vastatrix. 



As I limit myself here to a biological sketch of 

 the different species of Phylloxera, I will not enter on 

 an examination of the plastic characters which distin- 

 guish the grape- from the oak-lice. The form of the 

 impression on the third joint of the antennas, which is 

 elongated and oval in the oak-species, and circular in 

 the grape-louse ; is perhaps the most easy character to 

 seize. 



