340 
REVIEWS. 
8. Polythalamia, in which the cavities of the chambers do not directly 
communicate.— JDactylopora ; Acicularia . 
Perhaps the two last mentioned genera should constitute a sepa¬ 
rate family. But, as Dr. Carpenter hints, it is possible that we may 
yet discover the extinct forms which intervene between these and 
other Poraminifera; the existence of chains of affinities , binding 
together the most varied members of this group, having been now 
established in so many directions. 
Thus, from the systems of D’Orbigny, Schultze, and even of 
Lachmann and Claparede, the above classification differs in some very 
important features. On the other hand, in its most striking positive 
characteristics, it accords with the lately-published arrangement of 
Professor Beuss,* whose views as to the affinities of the Poraminifera 
would seem, for the most part, to have been the result of quite indepen¬ 
dent research. The following are the families admitted by Professor 
Beuss. Por the sake of brevity we have not given the names of his 
sub-families and genera : 
A. Poraminifera with imperforate shell,j - 
A. Shell arenaceous. 
1. Lituolidea. 
2. TIvellidea. 
JB. Shell calcareous, porcellanous, compact. 
1. Squamulinidea ? 
2. Miliolidea. 
3. Reneroplidea. 
4. Orbitulitidea. 
B. With perforate shell. 
A. Shell calcareous, vitreous, finely porous. 
1. Spirillinidea. 
2. Ovulitidea . 
3. Rhabdoidea. 
4. Cristellaridea. 
5. Rolymorphinidea. 
6. Cryptosteyia. 
7. Textilaridea. 
8. Cassidulinidea. 
R. Shell calcareous, with multiple pores. 
1. Rotalidea. 
C. Shell calcareous, traversed by a ramifying canal-system. 
1. Rolystomellidea. 
2. Nummulitidea. 
As to differences of grade of complexity among the Poraminifera 
it may be said that, as a general rule, to which exceptions exist, per¬ 
forate are higher than imperforate; Polythalamous than Mono- 
thalamous forms. Among the Imperforate we meet with membra- 
* Nachschrift to his ‘ Entwurf einer systematisclien Zusammenstellung der 
Foraminiferen.’ Wien. Sitz. October, 1861. 
t Reuss now places the Gromidce with Difflugia. 
