390 MR. F. CHAPMAN ON THE 
the upper (cleaner) surface, the bryozoa on the lower surface, 
whilst P. planum and P. miniaceum are on both surfaces. 
Off Tutanga, 60-100 fathoms (1898). 
Specimen A 35. 
A fragment of reef-rock measuring 7°5 x 4°5 cm., encrusted 
with Polytrema planum, which almost completely covers the 
specimen. There are also a few thin crusts of Lithothamnion 
Philippi var. funafutiensis associated with it, and an example of 
Cycloclypeus Carpenteri (form B), measuring 2°5 em. in diameter. 
The base of the rock is cavernous and drilled by boring 
organisms. 
Off Tutanga, 115-200 fathoms (1898). 
Carpenteria balaniformis very numerous on deep-sea corals 
(Oculinide). 
Off Tutanga, 117 fathoms (1897). 
Specimen A 32. 
A rough, irregular fragment of reef-rock, measuring about 
10x9x6 em., consisting of an aggregate of organisms, as 
foraminifera, minute corals, hydrozoa, and Serpule, solidified by 
intergrowth and encrustation. By far the larger mass of the 
rock is formed of the encrusting and cementing organism Poly- 
trema planum, which here still retains the pale green colour so 
frequently seen in living specimens. This green coloration gives 
to the Polytrema au illusionary resemblance to an alga. The 
large form (B) of Cycloclypeus Carpenteri is represented in this 
block by a specimen measuring 5 cm. in diameter, whilst there 
are numerous examples of the smaller form (A) embedded 
between the other organisms. 
Off Tutanga, 135 fathoms (August 1898). 
Specimen B7. 
A collection of reef-fragments ; consisting of some large masses 
of Polytrema planum (see Pl. 35. fig. 4), one or two measuring 
about 5 cm. square; some lamellibranch shells overgrown inside 
and out with Serpule and Polytrema planum, fungoid corals 
accreted with growing organisms, chiefly Polytrema planum ; a 
fragment of an alcyonarian stem measuring 4°5 cm. in length 
