some Species o/" Madrepora. 197 



It is interesting to note that the corallites of the immersed 

 calices usually have well-developed tabular stretching across 

 them completely, in spite of the septa, and that they are 

 tolerably regularly spaced and numerous. 

 Third species : — 

 The examination of a species of Madrepora, also from 

 Madagascar, confirms the statements regarding the exogenous 

 growth, its relation to the so-called ornamentation of spiuules, 

 the non-origin of bads from the calicular margin, the absence 

 of any unusual perforation in the wall of the parent corallites 

 for the origin of buds, and the comparatively solid laminate 

 nature of the principal septa. 



The species is Madrep)ora granulosa of MM. Milne-Edwards 

 and Jules Haime (Hist. Nat. des Corall. vol. iii. p. 156, 

 I860). 



It is not necessary to mention the specific details which 

 are given in the work just mentioned, but only to remark that 

 the very granular under part of the colony is remarkable for 

 the solidity of the structure beneath, and for the absence of 

 calices on that surface. The granules are really spinules with 

 expanded tops, and some are wider apart than otliers and 

 taller. They arise from a stout lamina which has a very iQ\y 

 perforations in it, and when the tops are decidedly expanded 

 the appearance given is very scale-like, the scales being very 

 close, but not in contact. In some places the expanded tops 

 are clearly in contact, and a new surface has begun to be 

 formed there. On making sections of the coral, concentric 

 laminge separated by radially disposed former spinules are seen 

 around the corallites, and they reach the surfaces, which arei 

 composed of the outer lamina and the spinules upon it.- The 

 density of the coral is very striking, and there is little tc 

 denote a perforate form. The upper surface is furnished with 

 numerous short, slender, not very proliferous ramuscules, arising 

 from a surface where spinules surround immersed calices, and 

 also some that are slightly prominent. The terminal corallite" 

 is rather long, stout, like all the others, without costse, and 

 has a rounded top of about o millim. in breadth, the calicular 

 opening being very small and only measuring 1 millim. broad. 

 The structure of this corallite is stout, made up of concentric 

 exogenously growing laminaj and spinules, and does not ex- 

 hibit the porosity of the similar corallites in the specimens- 

 already noticed. The outer surface is covered with a close 

 array of the characteristic spinules, and it is only in very 

 rare spots that a narrow opening occurs. Secondary corallites- 

 arise around the axial one, have the same shape, and oftert 

 the calicular part is minute and subnariform. Small buds- 



