THE 



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Tertiary ages, and which is almost extinct. The} 7 grow regularly and without the fission ; the buds 

 become polygonal as they grow upwards in company, and they mostly have a styliform columella. 

 Some of these were great reef-builders of old, and the buds and pai'ents were all united as a cellular 

 mass, by exothecal structures and by epitheca. One exceptional genus still flourishes, and in this 

 the buds, or corallites, are free above, and all united below by a dense growth, like an exotheca, the 

 growth being termed peritheca. It is the common Galaxea. 



The group Astrjeinse have spines and serrations on the free edges of the septa. It is a very unsatis- 

 factory division, but it is remarkable that the sub-families of the Eusmilinse are represented in the 

 Astrseinge, the difference being only in the septal structure. They are usually massive compound Corals, 

 and dwellers in shallow water and reefs. But there are some which are simple and solitary, and they 

 belong to the sub-family LithophylliaceaB, which, however, contains compound forms also. This sub- 

 family has some of its Corals in tufts and others in. lines or series more or less confluent, and these last 

 are subject to growth by fissiparity, the calices being often very long and curved, or meandriform. The 

 genera Montlivaltia and Antillia belong to the simple kinds, and the first has fossil and the second both 

 fossil and recent forms. The 

 tufted Montlivaltia group are 

 represented by the Mussas of 

 the warm seas of the great 

 oceans, and by the extinct 

 genera Thecosmilia, Rhabdo- 

 phyllia, and many others. 

 .Many massive Corals, with 

 many small calices arranged in 

 long, wavy, trough-like series, 

 exist amongst the meandriform 

 group, and are classified under 

 the g?nera Symphyllia, Myceto- 

 phyllia, Isophyllia; and in some 

 the septa! edges are extremely 

 spinulose. The very solid-look- 

 ing, wavy-caliced Mseandrinse 

 belong to this group, and the 

 common Corals so frequently 

 sold at sea-side places, with 

 slightly elongated deep calices, 

 belonging to the genera Lep- 

 toria, from the Red Sea and 

 Pacific and Indian Oceans. The 



Brain Stone Coral (Diploria cerebriformis) is one of these, 

 extinct genera are recorded. 



Another group of these ragged-topped septate Corals increase by the division of their calices, but 

 grow up in a solid mass, the division being restricted, and all the resulting individuals being united 

 together by exotheca. Some of these have the costse of one corallite uniting with those of their 

 neighbours, and pali may exist. Some Atlantic, Red Sea, and Pacific Ocean shallow water Corals of 

 this group are the Favise, and there are extinct species also. The lobed Goniastrsea belongs to this 

 series. 



The sub-family Astrseacese are Corals with spiny or serrate septal edges which reproduce by ova ; 

 but the individual is enlarged by a process of budding, which may take place from the outside of the 

 Coral, and from just outside the margin and from within the calice. The buds grow, and are united 

 by a dense exotheca, and the solidity of the whole is often increased by the costse of the corallites, 

 or separate parts of the mass, being united. The calices are separate in some genera, as in Heliastrsea, 

 and in such as bud outside the calice. Others, which bud within the calices or at the margin of 

 them, have polygonal, elongate, and even very confused calices, and they may be joined by the 



DIPLORIA CEHVBRIFOBXH 



Numerous fossil species of still existing or 



