46 A NATUBALIST'S WANDERINGS 



adjacent series; series about 2 millim. apart, calicles about 2 to 2'5 

 inillim. apart in the series. Calicle? forming, everywhere but on the tips 

 of the branches, low rounded elevations, by the gradual rising of the 

 surface towards their inferior margins to a height of '25 to ■? millim., 

 and occasionally by the similar but very slight elevation of their superior 

 margins. Calicles orbicular, looking upwards; orifice of adult calicles 

 •5 to -7 millim. in diameter ; oq the tips of the branches they ojwn on 

 the level of the surface of the corallum, are more or less imperfectly 

 defined from the surrounding loose ccenenchyma, and measure about '23 

 to '4 miilim. in diameter. Septa trabecular, consisting of vertical scries 

 of horizontal pointed projections from the wall of the calicle, beginning just 

 below its margin, di.stinct. Primaries about ■25 millipi. in length in full- 

 grown calicles, comprising two main, opposite ones, variously placed {i.e. 

 from parallel to the long axis to at an angle of 45° with the same), which 

 converge towards the bottom of the calicle, where they meet and form a 

 vertical plate ; the other primaries are slightly smaller and do not meet 

 below. Secondaries varying from about half the diameter of primaries to 

 mere points on the side of the calicle ; the secondary septum between the 

 two lateral primaries is sometimes wanting. 



~Corallum slightly vermiculate, always covered by minute points at 

 surface (at apes looser, very porous) ; the outer one-quarter of diameter 

 (except at apex, formed of a denser tissue, in which the calcareous 

 trabeculse exceed in diameter the spaces between them ; the central one- 

 half of the diameter {viz. usually about 2 millim.), consisting of a loose 

 tissue, in which the calcareous bars are only about half the diameter 

 of the intervening spaces ; the meshes of this tissue (as seen in transverse 

 section of a branch) elongate towards margin, smaller and relatively 

 shorter at centre. Apices of branches, to a distance of from 2-8 millim. 

 from the ends, formed of the looser axial ccBnenchyma, and carrying 

 more or less rudimentary calicles, which are at least 1 millim. from all 

 other calicles in the same longitudinal series. 



Hob. Keeling Islands, Indian Ocean ; deeper water inside reef. 



Represented by a single colony and a detached branch, which has 

 lived independently after its fracture from the parent specimen.* 

 They were collected and presented to the British Museum by Mr. H. 0. 

 Forbes, F.Z.S. &c., who has already (Troc Boy. Geogr. Soc, Dec. 1879) 

 described these islands, and with whose name I have much pleasure in 

 associating this new type. The chief colony measures 83 millim. (3^ 

 inches) in height, 100 millim. (4 inches) in greate.st breadth, and 55 millim. 

 (2|- inches) from front to back ; the detached branch, whicii bifurcates 

 three times, was about 60 millim. long when alive. Parts of the corallum, 

 owing either to an evanescent pigment or to traces of animal matter, l.ave 

 a most delicate pink tint. 



Some interesting points are brought out by the detached branch ; this 

 occurs unrooted, but obviously had been broken off from the colony 

 while yet alive, and lived subsequently free. As commonly happens in 

 such cases, the fractured surface has healed over ; but in this case the 

 new material is not a continuation of the superficial coenenchyma of the 

 adjacent side over the stump, but the prolongation outwards of the loose 

 central coenenchyma which has developed on itself five or six young 

 calicles. Here also the law of centripetal gemmation asserts itself, these 

 calicles occurring on the sides of a central cone of loose coenenchyma, of 



* See Moseley's 'Notes by a naturalist on Challenger.' "Some specimens 

 of this (Porites) species were xinattached, though living, being in the form of 

 rounded masses, entirely coveied with living polyps . . . and I suppose from 

 'time to time rolled over by the waves " : p. 311. [H, O. F.] 



