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NOTES ON RETICULARIAN RHIZOPODA, 35 
subdivided into three families, the other into seven, and the 
principal genera, perhaps all that were then known, are dis- 
tributed amongst these. Professor Max Schultze’s scheme 
is characterised by a somewhat wider grasp of the subject 
than its predecessor ; but with our present knowledge there 
is little to be said in favour of a classification that places 
Orbulina and Lagena in one of its two primary divisions, and 
Globigerina and Nodosaria in the other, or wherein Nodo- 
saria and Cristellaria are to be found in different families. 
There was, in fact, no practical advantage to be derived from 
it, and, so far as 1 am aware, it has been accepted by no 
subsequent writer. 
In the years 1861-2, practically simultaneously, appeared 
the memoirs containing the outlines of the two systems of 
classification which have been adopted, one or other of them, 
by the present generation of Rhizopodists. That Prof. von 
Reuss,! working on the Continent almost exclusively upon 
fossil specimens, and Dr. Carpenter with Professors Parker 
and Rupert Jones,? in this country, from the broader lines 
of the comparative study of living and fossil types, should 
have arrived independently at conclusions identical in their 
more important particulars, appears strong primd facie evi- 
dence that a reliable foundation, whatever the superstructure, 
had been at length reached. These papers are still the stand- 
point from which the discussion of the subject must be com- 
menced, and it is therefore necessary at the outset to state 
the general features of the schemes they embody, and by 
comparison, side by side, to show how far they agree in their 
details, and wherein they differ. 
The basis of the primary divisions of both systems is the 
minute structure of the shelly investment—a ground of 
distinction hardly recognised by previous authors. In 
general terms Foraminifera are divided into the same two 
classes—those with non-porous or imperforate, and those 
with porous or perforate tests. The former of these two 
divisions (Jmperforata) is in both systems subdivided into 
two sections, one including the types which have com- 
posite tests, that is, built up of sand-grains or similar extra- 
neous bodies more or less embedded in calcareous cement, 
the other having opaque, porcellanous shells of fine texture. 
In the division comprising the perforate or porous-shelled 
forms the agreement is less complete, as might be expected 
1 “ Entwurf einer systematischen Zusammenstellung der Foraminiferen,” 
‘ Sitzungsb. k. Akad. Wiss.,’ vol. xliv, p. 355. (The volume for the year 
1861, published, I suppose, in 1862.) 
2 «Introduction to the Study of the Foraminifera,’ London, 1862. 
