178 THE GREAT BARRIER REEF. 



A coral whose corallum may be said to represent a compound, arborescent, growth of a 

 simple Balanophyllia, is illustrated by the genus Dendrophyllia, of which two species are met 

 with in the Barrier district. One of these, Dendrophyllia axiftiga, Chromo plate VIII., Fig. 4, 

 may be gathered occasionally on the reefs in Torres Strait at extreme low tide ; but it occurs 

 much more plentifully in deeper water, where it commonly grows on the large mother-of-pearl 

 shell, Mckagrina niargaritifera, systematically collected by the divers. In its living state, the 

 corallum of this species is light golden-brown with a slightly greenish tinge. The tentacles of the 

 extended polyps, which are numerous and attenuate, are primrose or lemon-yellow, and the oral 

 centres a purer shade of the same tint. The second species, Dendrophyllia coccinca, Chromo VIII., 

 Fig. I, has been obtained more rarely by the author, under overhanging ledges of coral-reefs in the 

 neighbourhoods of both Thursday and Warrior Islands, in Torres Strait, and, in both instances, in 

 almost inaccessible positions, more or less completely screened from the access of daylight and very 

 rarely exposed to atmospheric influences. Notwithstanding its isolation from light, the colours of 

 the living corallum and associated polyps of this species are abnormally brilliant. The entire surface 

 of the corallum, and the membrane surrounding the oral orifice, are a bright brick-red, approaching 

 vermilion ; while the extended tentacles, which form a circlet of about forty-eight individual, 

 elements, representing five cycles, are elongate, subcylindrical, distinctly granulate and of a bright- 

 orange hue. It is worthy of note, before taking leave of the family of the Eupsammidas, that its 

 members are among the least prominent of reef-constructors. Many of its solitary repre- 

 sentatives are found in temperate and abyssal seas, two species, Balanophyllia regia and Stephano- 

 trochus Moseleyanus, being denizens of British waters. The second generic type, Dendrophyllia, 

 is represented in the Mediterranean by the large arborescent species Dendrophyllia ramea, which 

 form was dredged by the author off Setubal, on the Portuguese seaboard, from a depth of 

 600 fathoms, in the year 1870, in company with Lophohelia prolifera, Amphihelia oculata, 

 Hyaloncnia lusitanicum, Phcroncma Grayi, Askonema setubalense, and other deep-sea sponge and 

 coral types. The most remarkable fact connected with the deep-sea specimens of Dendrophyllia 

 ramea was that the corallum and polyps, when brought to the surface, possessed, in their 

 living condition, the same brilliant red and orange tints that characterise the shallow-water 

 Barrier Reef type above described. 



The members of the Madreporaria perforata pertaining to the family of the Eupsammidae 

 here enumerated, accord with one another in that their individual corallites are relatively 

 large, commonly measuring half an inch in width, and not unfrequently more. In the 

 family group that next offers itself for consideration, that of the typical Madreporidas, 

 represented by the genus Madrepora and its near allies, the individual corallites are of 

 almost microscopic minuteness ; and, if the single larger terminal calicle that characterises 

 the growing extremities of certain species be excepted, they rarely exceed one-eighth of an 

 inch in diameter. 



