122 MR. C. W. ANDREWS AND OTHERS ON THE [Feb. 20, 



Brook's type. Hence the identification is provisional. Some 

 variation in this respect exists between the specimens which 

 Brook classed under this heading (see Brit. Mus. Madr. vol. i. 

 pi. xxviii. figs. D & E). 



Pound in pools and channels near the edge of the reef-flat, 

 Flying Fish Cove. 



Genus Montipora Quoy & Gaimard. 



MONTIPORA SPONGILLA, sp. 11. 



Description. The corallum forms an erect spike about 5 cm. 

 long and from 1-1 - 5 thick, which flattens near the top and divides 

 into 2 to 3 or more similar spikes running up, side by side, or 

 diverging at very small angles. The calicles are minute, 05 mm., 

 but deep and conspicuous, about 1 mm. apart. The margin, 

 usually formed by a single skeletal thread, is round or slightly 

 petaloid. The septa not very well developed, except the directives, 

 one of which is usually specially conspicuous as a broad plate 

 which may or may not be slightly exsert. 



The smooth surface-ccenenchyma is a light friable reticulum, 

 very rough to the touch ; the tips of the branches are open flake- 

 reticulum and friable ; the coral is very light. 



This Montipore is peculiar, not only in its method of growth, 

 but also in its lightness and friability. There is one complete 

 stock. 



Occurs in pools on the reef-flat, Flying Fish Cove. 



Montipora parasitica, sp. n. 



Description. Corallum as a closely incrusting plate on other corals, 

 5 mm. thick, no free edges, but with a narrow smooth zone running 

 round the margin of the stock, 2-3 mm. broad ; within this zone the 

 whole surface is covered by tubercles. These are strikingly 

 variable and are in all sizes, from minute branching or frosted 

 granules to rounded or cylindrical tubercles, coarsely woolly, nearly 

 1 mm. high, here and there fusing into short ridges, and scattered 

 about in small patches. 



The calicles are very irregularly distributed, and vary in size 

 from •S-'lh mm. ; often obscured by the rough uneven tubercular 

 surface. The section is dense, built up of stout trabecule, and 

 wherever the surface tubercles are rubbed off, the solid stony 

 texture beneath is seen. 



The single specimen is nearly complete and incrusts the base 

 of the type specimen of Madrepora brooki. Among known 

 Tuberculate Montipores this seems to stand alone in manner of 

 ^rowth, and in the very variable distribution and development of 

 the tubercles. I believe many more small incrusting tuberculate 

 forms of Montipora will be discovered {cf. M. inconspicua). They 

 can be easily overlooked, and only attract attention when studied 

 under a -pocket-lens. 



11 fathoms. Flying Fish Cove. 



o 



