134 Mr. W. M. Maskell on some 
remarkably close to each other, with a variation only in the 
seventh joint, and as (from the descriptions given) there seems 
to be no other important differentiating character, these two 
will very likely be found to be identical, or, at most, varieties. 
In Section III. all the three species have nearly identical 
formule ; but there is a marked difference between the cottony 
secretion of D. herbicola and those of the others, and D. al- 
bizzie also differs a good deal im the same particular from 
D. hibbertiea. As for D. obtectus, whilst its formula is near 
to those of D. alpinus and D. Steeliz, the employment by it 
of the plant-scales as a shelter is amply sufficient for sepa- 
ration. 
2. The Genus Planchonia. 
For several years past I have been endeavouring to esta- 
blish the fact that all the forms which have been placed by 
various observers under the several names of Pollinia, Astero- 
lecanium, Lecaniodiaspis, Planchonia, are really only varia- 
tions or species of one genus; and I have affirmed that all 
these names, with the exception of Planchonia, ought to be 
abandoned. ‘To that opinion I still adhere; and the more I 
am enabled to examine insects of this kind, the more I am 
convinced that my view is correct. In this place I may 
observe that, whilst hitherto I have not devoted much space 
to Pollinia and Lecaniodiaspis, these two are not really 
different from the others. It has been thought by some that 
Pollinia is characterized by the absence of a marginal fringe ; 
yet it has precisely the same spinnerets as Planchonia, and, 
besides, the marginal fringe is by no means always con- 
spicuous in any species; I have seen a twig covered with 
scores of insects, of which at least half exhibited no fringe at 
all, while the rest had a very fine one. Lecaniodiaspis, on 
the other hand, is said to differ from Planchonia by the 
presence of antennz; but this, taken alone, and without any 
other distinguishing character to be made out, is surely an 
insufficient basis for the erection of a new genus, more espe- 
cially as in Planchonia itself the antenne are present, although 
in an atrophied or rudimentary form. 
Consequently I stand by the sole genus Planchonia as far 
as this particular section of Coccide is concerned. Now in 
my paper (Trans. New Zealand Institute, 1894) I have 
divided this genus into three groups :— 
1. Females having subcircular or elliptical tests ; 
2. Females having narrow elongated tests ; 
3. Females having irregular tests. 
