I70 THE GREAT BARRIER REEF. 



colour of which is a bright golden-yellow. The thickly interspersed projecting polyp 

 centres, together with their circlets of numerous subulate expanded tentacles, are a bright 

 purplish-pink. A coloured representation of this interesting type will be found in Chromo plate 

 VII., Figs. 4 and 4A. It is highly characteristic of this species that the branches of the coralla 

 exhibit a very marked tendency, in addition to anastomosing at all distal points of contact, 

 to fuse together laterally in such manner as to form dense fasciculi. The distal or growing 

 terminations of the branches also are usually much compressed, and are not unfrequently 

 somewhat triquetrous. With reference to the previously observed distinctive feature, it is 

 proposed to associate this species with the technical title of Ociiliiia fasciailata. A fragmentary 

 branchlet of a second species of Oculina was obtained by the author from one of the pearl- 

 shell divers in Torres Strait, at a depth of about seven fathoms. Its nearest affinities, as 

 worked out with the assistance of Mr. Brook, would appear to be with the Oculina arbiiscii/a 

 of Agassiz, a manuscript title associated with a species from South Carolina, of which a most 

 excellent figure, but no technical diagnosis, has been so far published. As attested in a 

 preceding chapter [aiifc, p. 72), many of the Oculinidas, including such genera as Lophohelia 

 and Amphihelia, are essentially deep-water corals, and form off the European coast, at a 

 depth of several hundred fathoms, banks that ma}' be acres or even miles in extent. 



The genus Echinopora includes three or four Barrier Reef species, one of which possesses a 

 solid semi-arborescent corallum, somewhat resembling that of an Oculina, while in the remaining 

 species the coralla consist of erect foliaceous expansions, comparable with those of Merulina. A con- 

 spicuous feature of all species of Echinopora is the sharply-pointed exsert character of the septa, and 

 the more or less spinous or echinulate nature of the raised ridges or costae that occupy the inter- 

 mediate areas between the polyp-cells. In the single semi-arborescent specimen of Ec/!i'i/o/>ora 

 liorrida (Chromo plate VII., Figs. 5 and 5^^), collected in the reef adjoining the Sisters Islands in 

 Torres Strait, the ramifying stem was in its thickest part about an inch in diameter, and of a golden- 

 brown hue, while the tentacles, as observed only in their semi-expanded state, were dark blue. 

 From the Palm Islands reefs, a little to the north of Townsville, two highly characteristic species 

 of the foliaceous race of this genus were obtained. In one of these, Echinopora rositlaria (Chromo 

 VII., Figs. 6 and 6a), the foliaceous coralla are erect and of such extreme tenuity that in their 

 bleached condition they appear to be constructed of paper. The ground colour of this coral in 

 its living state is most usually' a golden-brown ; but it is not unfrequently variegated towards the 

 bases of the inner surfaces of the corallum with shades of dark green. The polyp-cells art; 

 developed in the form of small, raised, circular rosettes, throughout the inner surface of the folia, 

 and, together with the tentacles of the associated polyps, are a distinct purplish-pink. This 

 species, in Milne Edwards & Haime's Histoirc des Corallaires, is somewhat inexplicably asso- 

 ciated with the two habitats of the Seychelles Islands and Van Diemen's Land. The 

 specimens assigned to the last-named locality were probably originally collected from the 



