MALAYAN PORITES. 187 
sometimes in double rows. The smaller ridges begin as low, thick mammille; these, when 
they have room to develop, swell above the neck into squarish flat-topped knobs, about 1 em. 
high and 1 em. broad, which may then lengthen to 2 or 3 cm. The depth of the living layer is 
7-8 cm. The small original base measures 2 by 3 em. 
The ecalicles are small, nearly uniformly 1 mm., slightly pitted near the tops of the ridges, 
but superficial down the sides. The walls are everywhere low, sharp ridges; on the tops 
(except where the calicles are opening in a streaming flaky reticulum) these ridges tend to be 
continuous membranes, but down the sides they are straight rows of small frosted granules, either 
resting upon a narrow irregular shelf of flakes or running along the edge of an obscure 
reticular thickening, The septa are short, thick, granular, and highly echinulate. There is a 
complete and conspicuous ring of septal granules often sharply separated from the walls, and, 
within, a ring of larger pali, which forms a central boss, visible to the naked eye. The 
formula seems to vary between those shown in Diagrams C and F, fig. 3 (p. 19). There is a 
small columellar tubercle, but all the elements seem to thicken rapidly, closing up the 
openings into the calicle. The fossa is therefore not deep or conspicuous. The small 
interseptal loculi are, however, deep and regular close round the wall. 
The section shows a streaming central flaky core, round which rather thin trabecule 
radiate regularly outwards; the latter are not very compact, and appear somewhat lamellate, 
especially as they leave the central core. The colour appears to have been a creamy yellow. 
The growth-form of this coral is interesting. There appears to have been no encrusting 
base, but the streaming layer of the skeleton seems to have carried the stock up irregularly 
into clusters of expanding ridges. The whole growth-form seems to be a complication of 
the expanding sheaf formation. Other specialisations of this have already been seen in 
P. Singapore 2,5,and 5. It is interesting to find so many Porites in this locality, for only 
one Goniopora, showing this specialisation of the skeleton. For other Porites showing traces 
of the same kind of growth, see Table III. 
Pa Zool. Dept. 78. 6. 6. 6. 
189. Porites Singapore (7. (P. Singaporensis septima.) (Pl. XXVIII. fig. 7; 
Pl. XXIX. fig, 1.) 
[Singapore,* coll. Raffles Museum ; British Museum. | 
Syn. Porites saccharata Briiggemann, Abh. Nat. Ver. Brem., v. (1878) p. 545. 
Description.—The corallum rises on a stalk into a close tangle of thick flattened stems, 
which bend and fuse together freely. The branchlets at the surface are long, thin, digitiform, 
and forking ; they point in all directions, and fuse together at all angles. They are 3-4 cm. 
long and about 1 em. thick. The living layer may extend some 12 cm. deep, and its lower 
edge tends to creep downwards. 
* Specimen ) with slightly different characters is from West Singapore. It is possible that 
they are all from the same locality. 
2B2 
