DISTRIBtrTION. 
93 
In Britain hardy species occur on the Scotch moun- 
tains, the moors of the Cheviot, the warm slopes of 
the tinder cliff of the Isle of Wight, and amongst the 
sheltered rocks of the Scilly Isles. In America Pro- 
fessor Eiley and Dr. Asa Fitch have described many 
indigenous species, and also have identified forms 
common to the continents of the old and new world. 
The American blight Schiozoneiira, and the vine Aphis 
Phylloxera, are examples sufficiently obvious to all. 
Dr. Shimer, in the ‘ Transactions of the American 
Ent. Soc.,’ vol. i, p. 283, describes under the new 
genus Hamameliotes, two remarkable species of 
Aphis, which form obliquely conical galls, and some- 
times mimick the form of the fruit of the witch hazel, 
Hamamelis Virginioe, upon which it feeds. Pemjphigince 
and other tribes also are natives of British Canada. 
It would appear from the statements of Captain 
Hutton, that no indigenous Aphides can be, or at any 
rate have been, detected in Hew Zealand, but that in 
1874 imported species were becoming very destructive 
to the crops. As we approach the tropics, the family 
Aphis appears to give way to Coccus and Cicada, the 
external forms of which are very remarkable, and appeal 
more forcibly to the eye than the less showy Aphis. 
Probably we shall hereafter find that the distribution 
of our British Aphides has followed the march of our 
Flora, and that the bulk of our insects will be chiefly 
tracked back to the northern and central parts of 
Europe. 
To assist the reader in naming the Aphides, a 
general synopsis of the Family has been prepared; 
and further, a table has been added, of the genus 
Siphonophora, by which it is hoped some clue, artificial 
though it be, will be given in a search amongst the 
species of this somewhat numerous genus. It is pur-^ 
posed to do the same with reference to the genus 
Aphis, whose members are still more numerous. 
