22 GILBERT C. BOURNE. 



which proves, however, to be exceedingly fragile, since the 

 polypes are borne on long calcareous stems, which readily 

 break off at their bases. Mr. A. Dendy, of the British Museum 

 of Natural History, has kindly identified the species for me, 

 which is described by Milne-Edwards and Haime ( f Nat. Hist, 

 des Coralliaires/ torn, ii, p. 333) as follows : 



" Corallites sometimes entirely free, sometimes united in 

 small series of three or four. Spines on the theca widely 

 separate from one another. Costse well defined in the region 

 of the calyces only. Columella rudimentary ; four cycles of 

 septa, the principal septa subequal, often decurved towards the 

 inner margins, which are scarcely at all dentate ; above they 

 bear three stout, diverging spines. The smaller septa have 

 tolerably regular, short, and pointed teeth. The polypes are, 

 according to Ehrenberg, of a pale brown, with a golden-yellow 

 disc. The margin is covered with bursiform papillae which 

 surround a small number of short digitate tentacles." 



To this I have to add that the number of septa is very 

 inconstant, and bears no relation to a multiple of six. In one 

 calyx I counted thirty-two septa, in another forty-six, in a 

 third (fig. 3) forty. In the last case twenty-four septa are of 

 conspicuously larger size than the remainder, but do not show 

 any characters which enable them to be classed as primaries, 

 secondaries, &c. Their shape is accurately shown in section in 

 fig. 3; the broader peripheral part can be distinguished from 

 the more slender central portion, and the processes connecting 

 the peripheral ends are easily seen. They are extremely 

 exsert, standing as much as 9 mm. above the lip of the calyx. 

 In the majority of cases one or sometimes two smaller septa 

 are found between each pair of larger septa ; these are thinner 

 and smaller, and of approximately the same breadth through- 

 out their course. Finding it impossible to separate the septa 

 into regular systems, I shall refer to the first as the principal, 

 the second as the secondary septa. The theca is formed by 

 fusion of the peripheral ends of the septa (see fig. 2), and is 

 only consolidated at some distance below the edge of the calyx. 

 The upper part of the corallite is smooth and polished, corre- 



