REPORT ON THE FORAMINIFERA. 
51 
B. With compact, porcellanous, calcareous 
SHELLS. 
1. Squamulinidea. 
2. Miliolidea. 
3. Peneroplidea. 
4. Orbitulitidea. 
B. Foraminifera with porous shells. 
A. With glassy, finely porous, calcareous 
SHELLS. 
1. Spirillinidea. 
2. Ovulitidea. 
3. Rhabdoidea. 
4. Cristellaridea. 
5. Polymorpliinidea. 
6. Cryptostegia. 
7. Textilaridea. 
8. Cassidulinidea. 
B. With exceedingly porous, calcareous shells. 
1. Rotalidea. 
Family — Miliolida. 
Sub-order — Perforata. 
Family — Lagenida. 
Family — Globigerinida. 
C. With calcareous shells, traversed by a rami- 
fied CANAL SYSTEM. 
1. Polystomellidea. 
2. Nummulitidea. 
F amily — N ummulinida. 
Yon Reuss’s classification, above quoted, is taken from the “Postscript” to 
the memoir referred to, in which the primary division into “ Foraminifera Monomera ” 
and “ Foraminifera Polymera,” adopted in the body of the paper, is abandoned. His 
family Gromidea also, which appeared in the original draft and corresponded with the 
Gromida of the English observers, is omitted entirely in the revised scheme. In the 
correlation of the two classifications, the principal discrepancy occurs in the Sub-order 
Perforata. The Lagenida and Globigerinida 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) Cassididinidea, together with one or two genera from other 
groups, find place amongst the Globigerinida of the British classification, and the family 
Lagenida is correspondingly reduced in extent. The family Nummulinida corresponds 
exactly with von Reuss’s section B, C. 
In his latest memoir 1 the same author 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 Foraminiferen C. Kiesel- 
schalige Foraminiferen; but its general features were left otherwise unchanged. 
1 Das Elbthalgebirge in Sachsen, 2ter Theil, 1874. 
