FROM THE LAGOON AT FUNAFUTI. 165 
By a reference to the foregoing Table, we find that the pre- 
vailing genus of the Foraminifera under all the varying conditions 
is Amphistegina. The specimens of this genus which are found 
in the middle of the lagoon are, as a rule, much smaller than 
those found within reach of the influence of marine currents from 
the outer side of the reef, whether through channels in the rim 
or through the submarine interstices of the reef-platform. 
The spurred forms Calcarina and Tinoporus (slightly resembling 
each other in general form but not related) are both common 
near the rim at Fuafatu Islet, and on the opposite side of the 
lagoon at Fongatale Islet ; but the latter genus rapidly dis- 
appears * on travelling across the lagoon, and Calcarina only is 
found in the various samples taken from the lagoon-floor. 
The number of genera of the Foraminifera found close to the 
lagoon-shore, near the Mission Church at Fongafale, is 21; but 
on the opposite side, at Fuafatu, the number is increased to 28. 
This is obviously owing to the greater influence of marine con- 
ditions and food-supply from the seaward face. At Fongafale 
this seems to be due to the passage of water through the reef- 
platform, and at Fuafatu to currents passing through channels in 
the rim of the Atoll or between the islets. — 
In the middle of the lagoon only three genera are present, 
namely, Sagenina, Amphistegina, and Heterostegina. 
Whilst the greater number of generic forms gradually die out 
towards the centre of the lagoon, a few, with some special varieties, 
make their appearance and in tolerable abundance, in consequence 
of the more tranquil conditions prevailing there. A noteworthy 
form in this respect is Carterina spiculotesta, whose tiny brown 
tests are usually found attached to Halimeda-fronds. The thin 
papery form Gypsina vesicularis var. squamiformis, and the 
adherent Planorbulina larvata are also found under similar 
conditions. 
PERCENTAGE COMPOSITION OF THE FoRAMINIFERAL SAMPLES. 
A Chart of the percentage composition of the samples with 
regard to the Foraminifera is given below. By this we see the 
almost equal proportion of Halimeda and the Foraminifera 
occurring near the rim of the Atoll at Fongafale Islet. There is 
* A solitary specimen of Tinoporus baculatus, much worn, and probably 
carried in by currents, was found in Sample 11, 3} miles from the rim of the 
Atoll. 
