266 ME. J. S, GARDINER ON THE PEHFOBATE [-A^PI"- 5, 



The coenenchyma consists of a dense reticulum, which early 

 solidifies, tending thereby to diminish the apertures of the calicles 

 and to further obliterate the septa. In the section of the column 

 the thin axial strand is hardly distinguishable from the cortical 

 layer ; both are very dense. At the tip of the growing stock the 

 reticulum may be lighter and run in parallel strise up the growing 

 point. The interstitial ramparts, which are more or less obliterated 

 towards the bases of the stock, are round and thick, but near the 

 growing point may be sharper and thinner. 



Rotuma ; boat-channel. Wakaya, Fiji ; lagoon. 



Under this heading two specimens, which appear to be 

 related, are grouped in spite of some important differences. 

 Superficial)}'^ they I'esemhle detached spikes of M. irreijuJaris from 

 Zamboanga. They difi'er, however, in the apparent absence of any 

 expanding and incrusting base, in the smaller size of the calicles, 

 in the chai-acters of the septa (which are very well developed 

 in M. irregularis), and in the density of the cross section. In 

 31. irregularis the spikes appear to grow rapidly and to be through- 

 out of a light spongy reticulum. In the coral under discussion 

 the growth is apparently slow and the corallum early solidifies. 



The two specimens differ in that the one from Eotuma has a 

 sharp pointed tip (with a few broken off spikes), the septa very 

 fully develojied and the coenenchymatous reticulum dense, even 

 right up to the growing tip ; while in the specimen from Fiji the 

 tip is a sharp flattened edge, the septa are rather better developed, 

 and the reticulum near the growing tip is lighter, more delicate, 

 striated as mentioned above, and the whole is more foveolate. 



The two specimens are classed together because the manner of 

 gi'owth appears to be the same, both have nearly solid section, and 

 the lower, more adult portions of the stocks are very similar. 

 Owing to the flattening of the interstitial ramparts near the bases 

 of the stocks, the specimens might perhaps be classed under the 

 heading glabro-foveolate. 



2. MoNTiPOEA rovEOLATA Dana (39). 



One specimen from Eotuma shows typical foveolation on one 

 side, but on the other the ramparts are broken up into curved 

 plates (c/. specimen c Brit. Mus. Coll.), which tend to rise above 

 the level of the surface (Bernard). 



Eotuma ; boat-channel. Wakaya, Fiji ; lagoon. 



3. MoxTTPORA sociALis Bernard (40). 



The specimen of this species differs from the type specimens in 

 the Brit. Mus. (which are fragments from the edge of a larger 

 stock) chiefly in being massive and of a closer consistency. The 

 ridges thinner, sharper, and taller (Bernard). The calices are 

 larger than in the type, being from 1-1"5 mm. in diameter ; 

 primary septa also distinctly larger than secondaries. 



Eotuma ; boat-channel. 



