FROM THE FUNAFUTI ATOLL. 21 
Subfamily CYCLOCLYPEIN. 
CycLocLyPeEvs, Carpenter [1856]. 
This genus is very restricted in its distribution. It appears 
to find its most congenial habitat in tropical areas where the 
water is practically free from suspended terrigenous material. 
From the investigations made round Funafuti we have learned 
of the remarkable and perhaps unique abundance of the various 
stages of this hitherto rare type. In point of fact only two 
other localities seem to have produced the larger form of C. Car- 
penteri, Brady, which often attains a diameter of 23 inches and 
merits the distinction of being the largest living foraminifer. 
The study of the Funatuti specimens at first presented no 
slight difficulty on account of the occurrence of so many appa- 
rently distinct varieties in the material examined. This, however, 
was cleared away by the discovery of the interesting fact that 
the whole of the series illustrates different phases or stages of 
one species, which is dimorphic *. 
In the course of obtaining additional knowledge regarding the 
coupling of species hitherto considered distinct, it seems most 
desirable to adhere to the principle of priority in the nomenclature 
of such dual forms, retaining the earlier of the two names for 
the pair. For example, in the following pages under the descrip- 
tion of the Funafuti specimens of Cycloclypeus, two already 
described species are included in one specific type as the two 
stages of that species; namely, C. Guwembelianus and C. Carpenteri, 
the former representing the young of form A, the latter appearing 
to include forms A and B. The latter species was not named 
by Carpenter, who figured, however, a large megalospheric 
specimen (A), whilst he described the exceptionally large examples 
from Borneo which are now seen to be the adults of form B. 
With regard to the name which the recent Cycloclypeus should 
now bear, the rule of priority in any case must be considered ; 
but in this it curiously happens that both species date from 1851, 
and since Carpenter figured both forms A and B, we may there- 
fore keep the name by which Brady designated Carpenter's 
original specimens, namely C. Carpenteri. 
The recent Cycloclypei are limited to the station off Borneo, 
where they were dredged from a considerable depth by Capt. Sir 
* In the sense employed by Munier-Chalmas and Schlumberger. 
