740 ME. J. STANLEY GABDINEE ON [JuDC 6, 



f'gure and tte above description. The section of the theca^ showing 

 profile of septa, is the same as in Dana's figure, but the upper 

 ends of the septa over the theca are generally more acute. The 

 valleys vary greatly in depth and breadth, in accordance with 

 the sinuosities of the surface of the colony. In breadth they vary 

 up to 4 mm. by about the same in depth, being always markedly 

 deeper than in my specimen of Leptorin fjrucilis. The septa on the 

 sides of the straight valleys distinctly alterntite in size, the smaller 

 not reaching the columella. Where the valleys are more sinuous the 

 arrangement, however, is not so regular, and often 3-5 contiguous 

 septa meet the columella. The columella is very similar to that of 

 L. gracilis, but the lobes on the surface are much lower, broader, 

 and less marked. 



Wakaya, Fiji ; reef. 



I am very doubtful whether this species is really distinct from 

 L. gracilis, as the differences might be almost explained as due 

 to different food-conditions in the two localities, as in the 

 specimens of Hydnopliora microcona from I'unafuti and Wakaya: 

 there are, however, no intermediate forms, nor can intermediate 

 calices be seen on the specimens. 



Genus Cceloeia. 



Cceloria, Milne-Edwards & Haime, Cor. ii. p. 411 (1857). 



Coeloria, Duncan, Eev. Madrep., Jour. Linn. Soc. xviii. p. 89 

 (1884). 



I have referred fifteen specimens to this genus, which is very 

 doubtfully distinct from the genus Maandrina. The chief differ- 

 ence, according to Martin Duncan, is that the columella in 

 Mceandrina is " formed of masses of spongy tissue, well-developed," 

 and in Coeloria " formed by trabeculse from the edges of the septa, 

 may be spongj\" If this view is correct, it implies that Mcean- 

 drina has a true columella, formed, as in Astroides calyculans, by 

 a deposit on tlie basal plate, ^hile in Coeloria the columella is a 

 secondary formation. Such a question can be settled only by a 

 study of the development, but in the adult colonies there does 

 not appear to be any real difference between the columella of the 

 two genera, except such as would necessarily follow from the 

 rather deeper, less sinuous, and thinner-walled valleys in Coeloria. 



The theca is formed in Ccelona by a thickening of the septal 

 sides. This thickening in a single colony may be plate-like, or in 

 the form of nodules joining the septa, later broadening and 

 forming a continuous wall, or A^ery narrow, the theca in this case 

 being formed mainly by a deposit of corallum on its upper edge. 

 There is hence no reason, as Duncan has supposed (Jour. Linn. 

 Soc, Zool. xvii. p. 363, 1884), for the separation of the species 

 C. 2^(tchychila Ehrenberg as the type of a new genus. 



The genus is very abundant on the lagoon-sboals at Funafuti, 

 where it forms large, spreading masses, which vary in colour from 

 brown to green. It is also found sparingly on the leeward reefs at 



