40 HENRY B, BRADY. 
The families proposed by Rupert Jones in his redivision of 
the sub-orders, with a view to remedying this defect, hardly 
meet our present requirements. Of Professor Zittel’s classi- 
fication I have had occasion to speak elsewhere! at some 
length, and I have nothing to modify in the views expressed 
at the time of its publication as to its merits and short- 
comings. 
Every attempt to arrange in single series a class of organ- 
isms of which the constituent groupsrun sometimes in several 
parallel lines, or even form independent circlets, morpholo- 
gically speaking, is of necessity open to objection at one 
point or other, and the aim of the systematist may be re- 
garded as attained if the anomalies and inconsistencies are 
slight, and are confined to particulars of the smallest zoolo- 
gical importance. In the scheme which I now venture to 
propose I have endeavoured to embody the views already in 
part expressed. In one or two not unimportant points it 
differs from that originally devised by my friends Dr. Car- 
penter and Professors Parker and Rupert Jones, but in its 
essential elements there is little or nothing that is incom- 
patible with the conclusions they have so ably expounded. It 
is put forward in outline, and with no pretence of complete- 
ness, in the hope that it may receive the criticism of natu- 
ralists whose pursuits qualify them to deal with the subject. 
The tabular summary needs, for the most part, but little 
explanation; the reasons for the course pursued, where it 
differs from that of other writers, are sufficiently obvious ; 
but there are a few points in which the method of treatment 
has been dictated by the study of the ‘‘ Challenger” collec- 
tions, and the further exposition of these must be left until 
it can be made with the assistance of the plates of the memoir 
now in progress. The nature of the investment of the animal 
—in other words, the texture of the test—has been to a certain 
extent abandoned as a primary distinction, though it is still 
employed in a modified way. Under all circumstances it is 
an important character, and in some families is distinctive ; 
but it will be seen that whilst there are certain families 
which are invariably arenaceous, and others which are in- 
variably calcareous and perforate, there are some in which 
no uniform rule obtains. 
A. Test imperforate, chitinous. 
I. Gromipa.—There has been much difference of opinion 
as to the zoological position of Gromza and its allies. So 
long as the animal of the Foraminifera was supposed to be 
' * Nature,’ Sept. 21st, 1876, vol. xiv, p. 445. 
