1898.] COEAI/S OP THE SOUTH PACIFIC. 275 



Funafuti ; passage in reef, 5 fathoms. 



The specimen is an incrusting growth 12 by 7 cm., in no part 

 seeming to be as much as 1 cm. thick. In places the edges have been 

 killed, and two pieces have thus been cut off, but were evidently 

 still alive when first obtained. The colour of the living colony 

 was green. The walls of the cells are studded, where three or 

 more meet, with the open ends of the calcareous tubes of some 

 worm ; these are about -4 mm. in diameter, and around many the 

 corallum has taken on an appearance as if they \^'ere lying in the 

 middle of a calice. 



9. PoEiTES EXiLis, n. sp. (Plate XXIV. figs. In & 8.) 



Corallum thin, incrusting, sometimes almost massive in the 

 centre, with a few mamillations ; growing edge about 1*5 mm. 

 thick, often free for 2-3 cm., closely followed by the epitheca, 

 which usually exhibits regular concentric markings. 



Calices shallow, about 1 mm. in diameter or 9 in 1 cm., 

 polygonal or more or less round, in some parts arranged almost in 

 lines. Cell-walls thin but, oOTng to the upper edges being 

 covered with spines, flattened at right angles to the walls, 

 appearing on the surface rather thick ; these spines are very 

 rugged and correspond more or less to the septa. Septa 12, 

 thick with rough sides, projecting into the calice for about a 

 quarter its diameter ; the upper edge, where it is attached to the 

 cell-wall, carrying a large, thick, rough spine, projecting con- 

 siderably into the cell and somewhat upwards, below these 

 running into the calice at right angles to the cell-wall. Inner 

 edges of primaries and secondaries often fused, and below 

 connected together by a ring of corallum, sometimes incomplete in 

 one part. Pali generally 6, fused to the septa, rough but some- 

 what pointed, with their summits little below the level of the top 

 of the wall. Erom the ring of corallum extend inwards a number 

 of elements which fuse in the centre of the calice, where the 

 columella arises, styliform but very rough, with its summit almost 

 level with those of the pali. 



In section the corallum is seen to be formed of rather coarse 

 elements, having the regular cross-palisade arrangement and 

 rather open meshes. 



Funafuti ; 7 fathoms. Eotuma ; 3 fathoms. 



There are three specimens from Funafuti, apparently from two 

 closely incrusting colonies, exhibiting typically the above arrange- 

 ment within the calices. The specimen from Eotuma has a few 

 low mamillations on the incrusting base ; while the calices over 

 the incrusting part are quite typical, those on these elevations 

 have their septa much thinner, arising higher up on the walls and 

 projecting straight into the cahces so as to often almost completely 

 obliterate both the large spine at their upper ends and the pali 

 fused to their free edges, the ring of corallum, joining which, is 

 usually higher up in the cell and more distinct. The colour of 



18* 



