18 MR. F. CHAPMAN ON FORAMINIFERA 
specimen of Polytrema often seen adherent to coral-rock, where 
the test bas formed a meandering surface-growth rather than an 
arborescent structure. 
Fig. 2.—Core from boring, Funafuti Atoll, at 766 ft. Containing nodules of 
Polytrema miniaceum yar. involva nov. Nat. size. 
P. miniaceum var. involva occurs in the coarse beach-sand of 
the outer reef-slope at Funafuti, and also at various depths in the 
deep boring. Its occurrence in the latter is of very great interest. 
These nodules of intergrowth are scattered throughout the more 
sandy parts of the cores of limestone down to a depth of 640 feet, 
when they are more frequent and of larger development. The 
largest and most typical specimens come from about 660 feet, 
where they are embedded in an Amphistegina-sand. They are 
common in the cores down to about 790 feet, after that 
occurring occasionally, and usually forming smaller nodules. 
P. miniaceum var. involva has also recently been noticed by the 
author in the Tertiary limestones of Christmas Island, associated 
with Orbitoides. 
Family NUMMULINIDZ. 
Subfamily NUMMULITING. 
Heterostecina, d Orbigny [1826]. 
HETEROSTEGINA DEPRESSA, d’Orbigny. (Pl. 3. figs. 6 & 7.) 
Heterostegina depressa, d’Orbigny, 1826, Ann. Sci. Nat. vol. vii. p. 805, 
_ pl. xvii. figs. 5-7 ; Modéle, no. 99. 
HI. antillarum, donna, 1859, Foram. Cuba, p. 211, pl. vii. figs. 4,9 25. 
