POLYNESIAN PORITES. 75 
portion of this is shown in Pl. VI. fig. 9, in the top 'left-hand corner, while the general type 
of the calicles on the upper surface is shown in the lower right-hand corner of the same figure. 
The other is on the under surface, and is the normal condition of the basal calicles; the wall- 
thread and granules are merely thickened, and the shelf of flakes is more conspicuous. The 
development of the shelf out of T-shaped flaky septal granules is not so clear in this form as 
as it sometimes is. Here and there the flakes come from the wall-ridge without any stalk, but 
their septal origin can be traced in many of the lateral calicles. 
In this case not only do the calicles differ from any of the preceding, but the growth- 
form, with its rather sharp ridge and valley system (see Pl. XIII. fig. 20), is also different from 
that of any other Funafuti Porites. 
a. Zool. Dept. 1904, 10. 17. 32. 
51. Porites Ellice Islands q712. (P. Hlliciana duodecima.) 
(Pl. VIL. figs. 2,3; Pl. XIII. fig. 21.) , 
[Funafuti lagoon ; coll. J. S. Gardiner; British Museum.] 
Syn. Porites arenosa var. lutea Gardiner, Proc. Zool. Soc. (1898) p. 273. 
Description.—The corallum is massive, and forms smooth, round, or oval stocks with closely 
adherent edges. 
The calicles are fairly uniform, in size about 1:25 mm., shallow, but with raised walls, The 
character of these walls varies enormously in different parts of the stock ; at one end the wall- 
ridge rises as a single straight wall obviously composed of fused trabecule, whose frosted tips 
look like compact rows of round granules. In this case the inner synapticular wall is hardly 
traceable, but the pali are thick, frosted, and rise as tall round-topped rods as large as the wall 
trabecule. Over the greater part of the upper surface of the stock the wall-ridge disappears ; 
it appears to melt down, apparently with an inner wall-ring, to form a‘rather close flaky 
reticulum (Pl. VIL. fig. 2), the elements of which only show a little frosting here and there. 
The septa in these calicles are very thin, but hardly smooth or straight. The pali are again 
large, and echinulate rather than frosted. On the lower parts of the stock this reticular wall 
tends to solidify, but shows traces of its median ridge. The pali are then less prominent, 
because surrounded by a ring of septal granules as large as themselves (see the asterisk on 
Pl. XIII. fig. 21). A third modification of the wall found in this specimen is unique within 
the genus (Pl. VII. fig. 3). The walls are flat and solid, but striated by the septa, which, 
when the walls are narrow, are arranged radially across them, when broad, as parallel lines— 
reminding one of the genus Agaricia. These strie project into the calicle as short thick 
septa, so crowded as to be almost in contact, and narrowing the calicle aperture, which is 
almost entirely filled by the ring of pali. 
L 2 
