FORAMINIFERA IN THE RAISED REEFS OF FIJI. 363 
Amphistegina occurs in eleven slides, and is often abundant, as is the 
case in the rock from Eua, 120 ft. 
Although rotaline Foraminifera occur in many of the slides, no form is’ 
common. The most generally occurring genera are Planorbulina and 
Truncatulina. Globigerina occurs in four slides. Orbitoides is of espe- 
cial interest, as it is not found in rocks younger than the Miocene. In- 
dividuals are very numerous in the section from Mango, 310 ft., and it 
is noteworthy that the genus is entirely absent from the other Mango 
specimens examined. 
The Niue rocks are characterized by the great number of tunicate 
spicules which they contain. The first described occurrence of these 
organisms as fossils was in the Pliocene of St. 
Erth, Cornwall, where Messrs. Kendall and Bell 
found spicules referred by Dr. G. J. Hinde to 
Leptoclinum.’ Professor Herdman had _pre- 
viously pointed out that calcareous spicules oc- 
curred in many genera of Tunicata, and were as 
capable of preservation as the aragonite skeletons 
of other organisms.? As, however, with the ex- 
ception of the St. Erth beds above-mentioned, 
: Fig. 18. Niue, Vailoa 
they do not seem to have been found in the 1h Waniesic spicule 
fossil condition, their occurrence in the coral (Leptoclinum), surface 
reefs of Niue becomes of interest. view, X 800. 
Although Niue (Savage Island) is situated between the Tonga and 
Fiji Groups, and the rocks of all three places resemble each other in 
structure and composition, the tunicate spicules appear to be confined to 
Niue (with the doubtful exception of Ngillingillah). They also occur, 
however, in the rocks from Christmas Island collected by Dr. C. W. 
Andrews, and in the Funafuti boring described by Dr. G. J. Hinde. 
In all three cases, Niue, Christmas Island, and Funafuti, the spicules 
seem identical and belong to the same genus, Leptoclinum Milne 
Edwards, as occurs at St. Erth. 
The number of spicules present in the rocks also varies widely. All 
the slides which are not simply sections of a coral mass, show some 
spicules, but they are particularly abundant in the black mud. In 
many cases, circular areas of clear granular calcite occur having the 
usual size of the spicules, but showing no structure. These clearly 
represent the spicules which have been altered into calcite aud their 
1 Quart. Journ. Geol. Soc. Lond., XLII. pp. 201-215. 
2 Proc. Geol. Soc. Liverpool, 1884-85, p. 42. 
VOL, XXXVIII. — NO. 8 2 
