22 MR. F. CHAPMAN ON FORAMINIFERA 
lets; but after two whorls of the shell have been completed, and 
while the test is still small, rudimentary secondary septation 
begins at the peripheral angles of the chambers, after the manner 
of d’Orbigny’s Heterostegina simplex *. The next stage in 
the septal division is seen after the completion of about four 
whorls, when straight, bar-like, but mncomplete cross-septa are 
seen projecting from the septum proper, but which do not 
extend for more than 3 across the chamber-cavity. In many 
specimens this incomplete septation is apparent to within the 
last few chambers, when it takes on the usual characteristic 
secondary septation of the Heterostegine type. 
One specimen of the complanate type (B) from Funafuti ex- 
hibits a remarkable variation in having the secondary chamberlets 
themselves divided at right angles by a third series of septal bars. 
The surface of the shell in this form (B) is usually granulate, 
or covered more or less with numerous hyaline papille, which are 
the rounded bases of cones of non-tubulous shell-substance, their 
points being directed inwards to the median plane. When the 
granules are arranged, as is sometimes the case, along the septal 
lines, we have the variation named by d’Orbigny 4H. costata f. 
Form A, on the contrary, always possesses a smooth-surfaced 
shell. 
Form B is found most frequently at a depth of 60 fathoms 
round Funafuti. 
In the sarecode of a megalospheric form, which was stained 
with picrocarmine, a nucleus with a nucleolus was observed, 
measuring 70 x 60 p. 
A microspheric specimen contained, in the middle of the 
sarcode body, a group of about a dozen rounded particles, pro- 
bably nutritive; whilst scattered through the body-substance 
there were seen six or more rounded algal cells (? symbiotic). 
H. depressa is not confined to the outer side of Funafuti. It 
is equally common in the lagoon, where it often attains as large 
dimensions as specimens from the outside. Very large specimens 
have also been noticed in some of the deeper cores of the boring 
in the atoll. It is especially noteworthy that the largest speci- 
mens of H. depressa found at Funafuti, measuring nearly 3 inch 
in diameter, were from dredgings at 32 and 386 fathoms outside 
Funafuti Atoll, N. of Pava (coll. by Prof. David). 
* D’Orbigny’s figures, however, appear to belong to form A. 
t Foram. Foss. Vienne, 1846, p. 212, pl. xi. figs. 15-17. 
