MADREPORARIAN CORALS 



79 



associated with the imperforate Caryophylha, so the com- 

 pound Dendrophyllia is found associated with Lophoheha. 



Dendrophylha has a very wide distribution. The most 

 famihar species, D. ramea, is found in moderately deep 

 water in the Mediterranean Sea and in the Atlantic Ocean, 

 and other species occur in shallow water on the reefs of the 

 tropical Indian and Pacific Oceans. D. ramea sometimes 

 attains to an enormous size. De Lacaze-Duthiers records 

 the capture, by the fishermen of La Calle in Algeria, of a 

 block of this coral a cubic metre in size. It also shows a 

 complex amalgamation of branches similar to that described 

 and figured for Lophohelia proUfera (see Fig. 5, p. 28). 



A critical examination 

 of the method of growth 

 of Dendrophyllia shows 

 that it is essentially 

 different from that of 

 Lophohelia. The great 

 branches of Dendrophyllia 

 are in reality enormous 

 calices with very thick 

 walls, on which the smaller 

 branches and calices have 

 arisen by lateral or thecal 

 gemmation. The calices 

 vary a great deal in size, 



as in all these corals, but in a typical medium-sized specimen 

 in the Manchester Museum they are about 10-15 mm. in 

 diameter. Each calyx shows a deep and wide cavity, at 

 the bottom of which a more or less well-developed columella 

 may be seen. The septa are thin, barely exsert, not very 

 wide, and those of the young cycles bend towards and fuse 

 with the older septa as in other Eupsammiids. 



The only account we possess of the polyps of a European 

 species of Dendrophyllia is that of D. cornigera, from the Golfe 

 du Lion, by de Lacaze-Duthiers, who says that the colour is 

 of a beautiful yellow-gold, the mouth being surrounded bv 

 a band of orange-red colour. The tentacles are very long 

 and of equal size and are dotted with little yellow spots. 



Fig. 3^. — Heteropsammia. Indian Ocean, 

 30 fathoms. Upper surface on the right, 

 showing the calyx. Under surface on the 

 left, showing the aperture formed by the 

 sipunculid worm. Nat. size. 



