172 
[January, 
ON THE SPECIES OF THE GENUS ORTHEZIA. 
BY J. W. DOUGLAS. 
Two years ago, Mr. Henry Chichester Hart sent for my inspection 
examples of an Orthezia he had found in Ireland, saying that they 
appeared to him to be identical with a species he obtained at Disco, 
North Greenland, which had been named for him Dorthesia chiton , 
Zett., that it also seemed to be the same as Coccus cataphr actus, Shaw, 
and requesting my opinion. My reply was that I believed it to be 
Orthezia Signoreti , E. B. White, that it seemed to agree with the 
species described by Shaw and Zetterstedt, and that both these latter 
and several others had been referred by Signoret, the latest writer on 
the subject, to Orthezia (Aphis) urticce , Linne. An article in the 
“ Entomologist ” for November, by Mr. Hart, on Dorthesia chiton , has 
been read by some of my correspondents to mean that I agreed with 
Signoret’s conclusion, but I merely stated a recorded fact, not having 
at that time investigated the question. It would be superfluous now 
for me to say this, but that it gives me the opportunity to offer some 
remarks indicating that two species are confounded under the name 
urticce. These remarks were prepared long since, but reserved, because 
Mr. W. E. Kirby informed me that Mr. Hart intended to work out 
the matter thoroughly. 
The species of this genus are dimorphous, that is, as in other 
Coccina, the males only are winged in the imago state. The following 
is the substance of Signoret’s summary of the peculiarities in the 
natural history of the apterous forms (Essai sur les Cochinelles, p. 
421) — particulars it is essential to know : 
“ We find examples having six joints in the antennee, these arc the young larva) ; 
others with seven joints, more or less equal in size ; others, also with seven joints, 
with a kind of scape, as in the llymenoptera ; finally, others with eight joints, these 
being the adult females. The individuals with seven joints have a peculiarity that 
we have not seen in any other genus (those in which the joints are of regular form 
are the female larva;), namely: that those with the scape have in all the legs the 
tibia and tarsus united, and thus form but a single joint. It is not, therefore, wonder- 
ful that authors have indicated a certain number of species, which, up to this time, 
we have not been able to find in the many places where we have collected these 
insects.” 
Of tbe apterous forms two kinds exist, for while in both the whole 
body, above and below, is covered with a close-fitting, wax-like (Sig- 
noret calls it calcareous), white secretion, and in both there is a wide, 
raised, segmented border formed of this matter, there are yet two great 
differences, constant throughout all the stages of life, in the other dis- 
