198 MADREPORARIA. 
rings can be perceived. When these rings do not rise quite to the surface, spike-like 
synapticule can be seen on the sides of the septa as if about to meet and complete the rings. 
There is very rarely any open fossa, and there are no pali. One, two, or three of the interseptal 
loculi are very large and conspicuous, as if to compensate for the absence of fossa. 
This specimen must be studied in comparison with others of the series. 
In No. 2, the same kind of calicles are found on the rather smooth out-curving basal rim, 
which consequently has the same soft, woolly appearance as this coral; but above this rim, the 
calicles and the character of the surface change completely. 
In No. 3, the basal rim and all the dead previous growths hidden under the base were of 
this same growth-form and with the same type of calicle formation. The calicles of the great 
stock above them change in the direction of those of No. 2, but never completely resemble 
them. 
Compare also the calicles of this with those figured for No. 6 (Pl. XXX. figs. 7, 8). 
a. Zool. Dept. 1904. 10. 17. 43. 
198, Porites Ceylon (922. (P. Ceylonica secunda.) (Pl. XXX. fig. 3; Pl. XXXV. fig. 30.) 
[Ramesvaram, coll. E. Thurston; British Museum. | 
Description.—The corallum, after the decay of the original base, rests free as a large column 
upon a disc-like basal rim slightly curved outwards. The nearly vertical sides are roughened 
all over by processes ; the small ones are mere rounded swellings, but they gradually change as 
they grow into stout vertical plates or short ridges with sharp edges. The top is irregularly 
flat, and consists of a crowd of short, sharp ridges, of all sizes arranged in every direction and 
fusing together freely. Between their steeply sloping sides are crevasses from 1 to 5 em. deep. 
The calicles are minute, the largest 1 mm., many as small as 0-5 mm.; shallow but dis- 
tinetly pitted, angular on the top but circular on the lower half of the sides of the stock. The 
walls on the top are continuous smooth threads, very stout in comparison with the size of the 
ealicle ; they stand a little above the general surface, and are nearly straight, showing a very 
slight tendency to be zigzag chiefly in the alternation of the septal points on each side. Down 
the lower half of the sides a tendency to form parts and then the whole of an inner synapticular 
wall appears, until on the upper surfaces and sides of the basal rim the calicles are exactly like 
those of the form last described, even with the large columellar tangle and the few enlarged 
interseptal loculi, The septa in the normal calicles come straight off from the walls as short, 
stout rods, which, when forming the lateral pairs, meet immediately in a blunt angle of nearly 
60°. The directives are very short. There are no pali, or only slight indications of them 
in some of the lower calicles. There is a short, thick, flattened columellar tubercle. For 
the details of the lowest calicles, see the preceding form. 
The section shows a very close arrangement of stout trabecule separated by rows of 
minute pores. The colour is a dull buff. 
