MADREPORA. 163 
2 to 5 proliferous corallites 2°5 mm. thick. Axial and proliferous corallites conical, 3 mm. at 
the base, tapering to 1‘5 or 2 mm. at the apex, 2 to 3 mm. exsert. Aperture of the corallites 
generally round, that of the nariform and tubular corallites usually smaller than in the others. 
A few axial and proliferous corallites have a slit-like aperture. Ccenenchyma porous; wall 
finely echinulate, indistinctly striate. 
I am inclined to regard the specimens recorded by Ortmann as M. valida, M. secale, and 
M. remota as varieties of this species, and, at any rate, all have many characters in common, 
The form referred to M. valida is rather cespitose than corymbose, but still shows the 
marginal branches more or less confluent. The specimens referred to M. secale have elongate 
horizontal branches fused into a plate. The type of M. remota differs chiefly in its plate-like 
habit, in having more distant branchlets, and near the centre of the colony a number of sub- 
erect, elongate, tubular twigs occur, which may be 2 em. long, 4 mm. broad at the base, and 
25 mm. at the apex. If I am correct in regarding this form as a variety of M. ceylonica, 
these elongate tubular twigs must be regarded as axial corallites on which lateral buds have 
not become developed. 
Ceylon ; ? Macclesfield Bank. 
a, 6. Ceylon. Haeckel Coll. 92. 12. 5. 17 & 31. 
c. Ceylon. Dr. Ondaatje [P.]. 83. 4. 26. 3. 
d. Ceylon. Haeckel Coll. 92.12.5.21. (? M. remota, 
Ortm.) 
?e. Macclesfield Bank, 18 to 28 fathoms. H.M.S. ‘ Penguin” 92. 10. 17. 78. 
173. Madrepora tumida. 
Madrepora twnida, Verrill, Comm. Essex Inst. 1866, vol. v. p. 21; ibid. 1870, vol. vi. p. 102; Rathbun, 
Proc. U.S. Nat. Mus. 1887, vol. x. p. 19. 
Corallum corymbose, the branches coalescing into a broad massive base, supported by 
a thick peduncle, the upper surface flattened. Towards the margin the branches spread 
horizontally, and gradually become loosely coalescent and free ; from the whole upper surface 
arise numerous nearly upright branchlets, which are rather stout, about 5 em. high, tapering 
rapidly, and mostly divided into several small secondary branchlets. Radial corallites large, 
thick, and turgid, somewhat appressed; the cells large, opening upwards, conspicuously 
stellate, with 12 septa, of which the secondary ones are much the narrowest ; two directives 
nearly reach the middle line. Axial corallites somewhat larger than the radial, exsert, the 
margin thick, very porous; primary septa equal, secondaries well developed. The cells at the 
base of the branches are wholly immersed, but have 12 conspicuous septa. On the lower 
surface there are very few cells; these are very small and wholly immersed. Surface of the 
coenenchyma openly reticulate and porous, with spinous granules; exterior of corallites 
densely covered with small lacerate spines. Breadth of largest specimen 46 cm., height 
12°7 cm. (Verrill.) 
