NOTES ON RETICULARIAN RHIZOPODA, Oo” 
omitted entirely in the revised scheme. In the correlation 
of the two classifications, the principal discrepancy occurs 
in the sub-order Perforata. The Lacenipa and GuosicE- 
RINIDA together are almost exactly coextensive with Von 
Reuss’s two sections B, A and B, but the (1) Spirillinidea, 
(2) Ovulitidea, (7) Textilaridea, and (8) Cassidulindea, 
together with one or two genera from other groups, find 
place amongst the GiosicErinipa of the British classifica- 
tion, and the family Lagenipa is correspondingly reduced in 
extent. The family Nummurinipa corresponds exactly with 
Von Reuss’s section B, C. 
In his latest memoir! Von Reuss again somewhat modified 
his arrangement, making three primary groups of equal 
zoological value, and reversing the order originally adopted, 
thus :—A. Kalkschalige Foraminiferen, B. Porenlose Foramini- 
feren, C. Kieselschalige Foraminiferen; but its general fea- 
tures were left otherwise unchanged. 
It will be seen at a glance that the “ families” of the 
German arrangement are much smaller and more numerous 
than those adopted hy the English naturalists, but this is 
counterbalanced by the more comprehensive “ generic 
types”’ of the latter. The essential difference, not only 
between the two systems of classification, but in the entire 
methods of study and nomenclature, is to be found in the 
different values of their respective ‘‘ genera” and “ species.”’ 
Before proceeding to any further remarks upon these, we 
may notice briefly two other schemes of classification which 
have been suggested comparatively recently, one by Pro- 
fessor T. Rupert Jones,” the other by Professor Carl Zittel.* 
Their general features will in like manner be best understood 
from tabular summaries. 
1 «Das Elbthalgebirge in Sachsen,’ 2ter Theil, 1874. 
2 « Monthly Microscopical Journal,’ No. 86, Feb., 1876, pp. 89—92. 
3 «Handbuch der Palaontologie,’ vol. i, pt. 1, 1876, pp. 61—106. 
