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Show 1899.] CORALS F R O M FUNAFUTI. 51 seen the ' Challenger' specimen, and consider this to be the same form. Previously recorded from south of Papua, off the Ki Islands, depth 140 fathoms ; and Port Molle, Queensland. Family PLEXAURID^E. EUPLEXAURA ANTIPATHES Klunzinger. (Plate IV. figs. 1, 2.) Plexaura antipathes Klunzinger. This specimen, which is in a dried state, is pale fawn in colour. The colony is much branched, the branches arising approximately in one plane. The branches are given off irregularly; they, in their turn, branch repeatedly, and these branches bear further branches. There are no traces of anastomoses. The basal portions are slightly flattened, but the terminal twigs are round and thicken slightly towards the ends. The branches run close together and fairly parallel. The polyp-pores are scattered irregularly over the whole surface, and are not raised above the general level except on the terminal twigs, where they are at the summit of slight conical elevations. They are about 1 mm. apart. The cortex is friable, and somewhat thicker on the twigs than the older parts. It is comparatively smooth; on the older branches there are slight longitudinal furrows which run somewhat spirally round the stem. The axis is of horn, with scattered particles of calcareous matter ; it is of a dense black colour in the thicker branches. The " root" portion of the colony shows a great development of a peculiar skeletal substance, hard, and looking like stone. It is dull grey in colour, and shows the same furrowings as the cortex of the stem which extended over it. On treating with acid the stony part is dissolved away, leaving a fine network of horny matter in which the CaC03 was contained. The grey substance which strengthens the base of attachment is clearly formed independently of the black axis, although it may rightly be regarded as being of the same nature. Judging from the dried specimen it is composed of spicules of lime embedded in a horny matrix, no processes of the ccenosarcal canals extending into it, even superficially. It is extremely hard, and breaks with a clean fracture when struck with a hammer. The horny axis, on the other hand, can be cut with a penknife. The nature of the horny substance is not determined, but from its insolubility seems similar to the keratin of the axis. It is only rarely seen in specimens of Gorgonacea in Museums, although it is possible that it may be formed at the base of all large Gorgonids when exposed to strong tides. In the centre the calcareous matter is white and friable, not having assumed the stony, solid appearance of the outer part. The basal enlargement is seen also in Plexaura principalis and P. suffmticosa, in the National Collection at South Kensington; 4* |