﻿FOVEOLATE MONTIPOR^. 67 



with six clear, round, petaloid, interseptal loculi, not always symmetrically arranged, and with 

 occasional rudimentary septa of the second cycle faintly indicated. 



Ccenenchynia in sections of younger branches shows a thin axial streaming layer, 

 delicate and open, in sharp contrast with the radial or cortical layer which tends at once to be 

 dense. In older branches, both elements are very dense, and the cortical layer is thick and 

 very solid. On the surface, the cffinenchyma sends up on the younger branches ragged flakes 

 which tend to form what appear to be thin, protuberant underlips to the calicles; but these 

 really rise from the middle of the interstices, and as the branches thicken grow right round as 

 low, almost hexagonal ridges, often in sharp contrast to the level solid layer out of which the 

 calicular aperture is cut. To the naked eye, these ridges look solid, but under the lens they 

 appear beautifully serrated and frilled. 



Dana's figures and description apply exactly to a specimen from the Fiji Islands which 

 was accordingly identified as M. jMlmata by Quelch. There were, further, four other speci- 

 mens also from Fiji which are not quite so typically palmate and which were named by 

 Quelch 3L rubra, Q. & G. These show, however, the same specialisation of the ccenenchyma, 

 and cannot be separated from the palmate specimen above alluded to. The differences may 

 be accounted for by different stages of growth ; the more ragged palmate specimen is altogether 

 younger and in more vigorous growth, and the surface ccenenchyma has not yet assumed the 

 final character above described. Examination of its dead basal part shows that this identifi- 

 cation is correct, for the corroded calicles can be easily seen to be enclosed within the typical, 

 clear, sharp, hexagonal ridges running down the middle of the interstices. 



Lastly, a specimen labelled " Montipora levis, variety " seems to me to be closer to this 

 type than to M. levis, although the protuberant interstices are obscured and the whole ccenen- 

 chyma is thick and dense. The calicles are alike, and on the sides of the stem there are clear 

 traces of the formation of the tjrpical ridges surrounding flat polygonal areas. 



The resemblance of some of the smaller and thinner branches with their nariform pro- 

 tuberant ridges to the branches of Madrepores is very striking. 



In his figure 26, Dana represents an enlarged polyp fully expanded, the twelve tentacles 

 like equal, flat, marginal lobes coloured alternately brown and light blue, the former being the 

 general colour of the animal, the latter forming a thin band round the oral aperture. 



For Quelch's suggested affinity between this type and his M.fragilis see p. 139. 



a. (An old clump) Fiji Eeefs. . H.M.S. ' Challenger.' 86. 12. 9. 283. 



&. (Stock with fresh tip in rapid growth.) „ „ 86.12.9.257. 



c. (Young stock encrusting corroded „ „ 



previous growth.) 



d, e, f. (Portions of small stocks.) „ „ 



g. (With typical characteristics greatly [Ptegister No, 86. 12. 9. 358.] 



obscured.) 



K 2 



