532 J. W. Gregory & Jean B. Trench— 
a columella, as that course has been adopted for the recent Montipore 
it seems advisable to follow it. 
The genus Montipora is confined in range to the western Pacific, 
Indian Ocean, and Red Sea. A fossil specimen has been recorded 
from the raised beaches of the Gulf of Suez (Gregory, 1906, p. 117), 
and a living species from the Pliocene of Borneo (Felix, 1918, p. 326); 
but otherwise it appears to be unknown fossil. The occurrence of 
this Eocene Montiporid is of interest, as it throws light on the 
disputed question as to the affinities of the family. According to 
Dana (1848, p. 490), Montipora (which he calls MManopora) is 
a degenerate MMadrepora. This view has also been accepted by 
Bernard (1897, vol. iii, p. 12). Milne Edwards and Haime, on the 
other hand, regarded Montipora as a Poritoid with an abundant 
coenenchyma; and this view has been adopted by Duncan. ‘The 
essential difference between the Poritide and the Madreporide 
appears to be the character of the septa. In Madrepora they are 
lamellar ; in the Poritide they are reduced to irregular trabecule. 
In this characteristic Jfontipora is more similar to Porites than 
to Madrepora. Bernard argues that the characters which give 
a trabecular character to the coenenchyma of JD/ontipora are shown 
by his investigations to be secondary structures. It might therefore 
be inferred that the trabecular nature of the septa is also secondary. 
But in the Eocene Montipora the septa are spines and not lamelle ; 
this characteristic was fully developed in the earliest known species ; 
and that fact supports the view that the Montiporide are more 
nearly related to the Poritide than to the Madreporide, 
Tue Ace anp RELATIONS oF THE FAUNA. 
The affinities of this fauna as a whole, with the exception of the 
one Cretaceous species, are Eocene, but geographically it is too 
isolated to be satisfactorily referred to the precise subdivision of 
that system. Mr. R. B. Newton, who is kindly describing the 
associated foraminiferal limestones, tells us that their age is probably 
Lutetian (Middle Eocene); and the coral fauna is consistent with 
that opinion. 
It has been long known that New Guinea includes a rich and 
varied series of Kainozoic deposits, which range from the Eocene to 
the Pleistocene. They include thick beds of foraminiferal limestone 
which in Dutch New Guinea form precipices (Rawling, 1911, 
p. 244, and Wollaston, 1914, pp. 257, 265) that have been described 
as the loftiest in the world. ‘The rocks have a general trend east 
and west, and they are represented by similar rocks on the western 
islands of Malaysia. . 
The best known of the Kainozoic deposits of New Guinea are the 
foraminiferal beds, which include Eocene limestones with Wummulites 
and Alveolina, Miocene orbitoidal limestone, and in the Upper 
Pliocene or Pleistocene widespread foraminiferal oozes or marls 
(e.g. Schubert, 1910, p. 326), which indicate an extensive subsidence 
in very recent geological times. A valuable summary of the informa- 
tion regarding these foraminiferal limestones and full references to 
