Genera and Species of Coccidex. 137 
easily one can mistake a Psyllid for a Coccid by considering 
only the waxy pupal test; and if it is so easy to make such 
a mistake between two different families, how much more so 
would it be to confuse two species of the same genus. ‘There 
is little risk of such a thing if the characters of the insects 
themselves are made the principal points of separation. 
3. The Antennal Joints of Coccide. 
The study of Coccids differs from that of most other insects 
in that, as a rule, their extreme minuteness obliges us to 
adopt means of classification which are not necessary amongst 
the Lepidoptera, Coleoptera, &c. Moreover, in a large pro- 
portion of cases they not only are so covered by different 
kinds of secretion as to make it nearly impossible to judge 
from external marks or colours on the epidermis, but also 
usually shrivel up and become deformed at gestation, so that 
their very form is not a sure guide. Consequently, in order 
to arrive at anything like a clear classification, we have to 
use such characters as the number of antennal joints, the 
arrangement of certain hairs or processes, the form and 
proportions of the feet, and so on—things which, to a lepi- 
dopterist, for example, would seem absurd and useless. 
In a very interesting paper by Herr Karel Sulc, published 
at Prague in 1894, on a new Coccid named by the author 
Ortheziola Vejdovskyt, it 1s stated that one of the characters 
separating this from the genus Orthezia is “the number of 
joints of the antenne (in Urthezia 8-9, in Ortheziola 3 only) ,” 
and in the description of the insect Herr Sule says: ‘ the 
head is furnished with two frontal processes, to the apex of 
which are attached the antenne.” In the excellent plate 
appended to the paper the antenne and the ‘ processes” are 
clearly shown (figs. 2 and 8). 
I have ventured to draw the attention of Herr Sulc to the 
fact that in this description he is departing from the usual 
custom of students of the Coccide, which has hitherto been 
to consider what he terms the “ frontal process’ as the first 
joint of the antenna. I cannot affirm that the rule is abso- 
lute and universal, as there are exceptions; but it has been 
followed by such authorities as Signoret, ‘T'argioni, Comstock, 
&e., and, I think, by all the modern writers. Indeed, Herr 
Sule, in the sentence quoted above, ascribes to the adult 
Orthezia “ 8-9 joints,” which cannot be, unless the “ frontal 
process” is counted as one; and in a paper of his own, in 
the ‘ Entomologist’s Monthly Magazine,’ February 1895, he 
