182 MADREPORARIA 
SINGAPORE. 
183. Porites Singapore ~1. (P.Singaporensis prima.) (Pl. XXVIII. fig. 1; 
Pl. XXXV. fig. 19.) 
[Singapore,* coll. Raffles Museum ; British Museum. | 
Deseription.—The corallum is massive, the upper surface rising into rounded humps 
which overhang the base. _ As the mass grows in size, these humps seem to grow out to form 
rounded cushion-like edges, 2°5 cm. thick, free of the early growths, and sheltering them as 
under an umbrella. The earlier growths may be found overturned. The living layer may 
extend 3-4 cm. under the projecting edges of the stock. 
The calicles average 1 mm. in diameter, conspicuous because sharply sunk. The walls 
are sharp, simple, straight, slightly denticulate, a nearly regular lattice-work ; only on the tips 
of mounds or where mounds are just beginning to appear calicles occur having reticular walls 
with young buds appearing in the angles. On the under surfaces, the walls are faint rows of 
flattened granules forming straight ridges between shallow funnel-shaped calicles. 
The septa are thin and finely echinulate ; they appear just below the edges of the walls 
and slope with ragged edges—indicating the presence of septal granules—into the fossa. The 
pali form an irregular inconspicuous ring of frosted or echinulate points, rising no great height 
in the fossa. The four lateral principals are moderately developed ; the directives are seldom 
large. The full formula is often traceable. 
The interseptal loculi are large and open, and the fine lateral echinul of the septa can 
be seen to unite to form a delicate network, which, as an open columellar tangle, sometimes 
rises into view. The central tubercle is very thin, delicate, and flattened. 
The section seems to be finely and closely trabecular. The colour of the unbleached stock 
is a warm grey. 
There are three specimens, which seem to belong together. 
a. The smallest shows a basal fracture about 5 cm. across; above this, the lateral 
swellings extend some 12 em., while the top, which is 10 cm. above the base, runs out into 
short thick humps. The living layer only descends some 6 cm. Some five previous growths 
seem to be enveloped or capped by the last colony. A boring sponge has made them quite 
rotten. The calicles appear to be slightly larger than 1 mm. 
a. Zool. Dept. 98. 12. 1. 28. 
b. Shows a basal section of about 4 cm., above which the knobbed mass expanded more 
or less evenly and rapidly for 16 cm., the lateral out-growth projecting quite horizontally 
* Specimen c is said to be from West Singapore, and this is probably the locality of the other 
two specimens as well. 
