MADREPORARIAN CORALS 97 



the Old World, but absent in the Atlantic Ocean and West 

 Indian waters. Many specimens are of very great size, and 

 almost every possible form of growth such as the branching, 

 encrusting, massive, foliate, etc., may be represented. One 

 particular form of this coral was called by Rumphius 

 Elephant Ear and others Sea-rose or Sea-cauliflower. These 

 varieties are described by Pallas under the name Madrepora 

 joliosa. 



There is no difftculty in determining at once, by the 

 examination of a dried specimen with a hand lens, that all 

 parts of the colony are profusely perforated. 



The calices are small, rarely exceeding i mm. in diameter, 

 and do not project above the general surface of the corallum. 

 The genus can be distinguished from Porites, with which it 

 is most likely to be confounded, by the presence of a con- 

 siderable amount of coenosteum between the calices, per- 

 forated by numerous and relatively large pores. 



The details of the calicular structure are more difficult 

 to ascertain, not only on account of their small size, but 

 because the septa are reduced by perforation to rows 

 of minute spines or trabeculae of great variability. An 

 examination of a large number of cahces, however, leads to 

 the conclusion that six primary septa are always represented 

 and usually six secondary septa as well. In some specimens, 

 but not in all, the two directive septa of the primary series 

 are larger than the others and meet in the centre of the calyx. 



According to Saville-Kent the colours of Montipora on 

 the Barrier Reef are almost as brilliant and as varied as the 

 colours of Madrepora. 



Anacropora, a genus confined to Indo-Pacific seas, is in 

 some respects intermediate between Madrepora and Monti- 

 pora. It has a characteristic method of growth, thin branches 

 diverging at wide angles which tend to form tangled masses 

 of low growth. 



The walls of the calices protrude from the surface, and 

 there are definite septa and costae as in Madrepora, and the 

 calices are separated by coenosteum as in Montipora. 



TuRBiXARiA. — The genus Turbinaria is generally classified 

 with the Madreporidae. It differs, however, from the other 



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