MALAYAN PORITES. 159 
the side of some rock. There are so many calcareous worm-tubes opening on its surface, that 
it is possible that the coral may, in some way, owe its shape to them. They may become 
attached to the lower surface of the projecting coral, and then, curving upwards towards the 
light, become slowly grown round. 
a. Zool. Dept. 84. 3. 7. 1. 
155. Porites Banda Sea 1. (Porites Banda prima.) (Pl. XXV. fig. 3; Pl. XXXV. fig. 7.) 
[Banda, coll. H.M.S. ‘Challenger’; British Museum. | 
Syn. Porites arenosa (partim) Quelch (non Esper), Chall. Rep. xvi. (1886) p. 183. 
Description.—The corallum appears to envelop some prominence or ridge of the substratum 
(dead corals, worm-tubes, shells, ete.), and to swell into an irregular knob with rounded 
humpy surface. The lower edges closely adhere and descend 5 cm. 
The calicles are minute, sub-circular, 0°8 mm, in diameter, shallow, but definitely and 
sharply pitted. The walls are occasionally single and raggedly zigzag, often membranous 
but mostly they are irregularly reticular, apparently filamentous, but really membranous 01 
flaky ; at times the flakes, tilting sideways, are conspicuous along the tops of the walls. The 
septa are long, and, seen from above, filamentous, slight, bent, angular, but with few echi 
nulations. They soon join a large, very open columellar tangle of fine threads ; its topmost 
elements are the partial rings which join the pali; below this level fresh rings can be seen in 
the interseptal loculi, making larger circles. Pali, granules on the walls and septa, and a central 
tubercle begin to appear in the calicles on the sides, and, though very irregular, are most 
developed near the lower edges of the colony. The circle of pali is large. The pali them- 
selves begin as ragged flakes, or as plates, but turn into rods. The formula seems to be 
complete, but it is irregular. 
The section shows a rather dense trabecular structure somewhat obscured by the lamellate 
character of the otherwise rather delicate trabeculae. The remains of a yellowish fawn colour 
ean be seen. 
This coral is interesting because, though very unlike the specimen last described, analysis 
shows it to be a closely allied form. 
a. Zool. Dept. 86. 12. 9. 363. 
156. Porites Banda Sea (2)2. (Porites Banda secunda.) (Pl. XXV. fig. 4.) 
[ Amboyna, coll. H.M.S. ‘ Challenger’ ; British Museum. | 
Syn. Porites palmata (partim) Quelch (non Dana), Chall. Rep, xvi. (1886) p. 180. 
Description.—The corallum is branching, forms short stems slightly compressed, about 
1 cm. thick and1°5cm, broad. The stems fork at an angle of 60°, the branchlets being about 
