212 CEYLON PEARL OYSTER REPORT. 



Moseley. Semper (49, p. 263), in discussing the validity of his genus Rhodopsammia, 

 makes reference to the difference in the septal characters of the former species as 

 shown in Milne-Edwards and Haime's figure (36, plate i., figs. 6, 6a), but it 

 requires no great amount of ingenuity to show that the difference, great as it may 

 appear at first sight, is really nothing more than a slight variation of the grouping of 

 septa developed according to the sequence established by Pouktales and Duerden. 



It is possible that the specimen here referred to Balanophyllia, is nothing more 

 than the initial individual of a colony of Dendrophyllia, and the two lateral buds 

 lend some support to this view. On the other hand, the buds, both from their 

 position and character, might very well be similar to those of B. socialis or parallela, 

 and as the specimen is a solitary one, I have |)referred to refer it, provisionally, to the 

 same genus. 



Lobopsaminia, M. Edwards and Haime (36). 



The small colony shown in Plate II., fig. 10, agrees very closely with the definition 

 of this genus, hitherto represented only by fossil forms. The structure of the 

 corallites, however, is so similar to that of Balanophyllia cumingi that it is hard to 

 draw any distinction between them ; the septa and columella are almost identical, 

 and the most that can be said is that the costse are smaller and the theca decidedly 

 thinner than in the latter species. If this specimen must be separated from Balano- 

 phyllia on account of its colonial habit, it must be placed with Lobopsammia rather 

 than with Ccenopsammia because of its elliptical calices and because the mode of 

 aggregation of the colony suggests that it has been formed by fissiparity rather than 

 by gemmation. Moreover, its likeness to L. cariosa, Goldfuss (25, taf. xiii., fig. 7), 

 is sufficient to establish its generic position. 



Lobopsammia robusta, n. sp. Plate II., figs. 10 and 10a. 



Colony consisting of a few corallites borne on a very thick and short stem. The 

 individual corallites short, radiating outwards from the stem. Calices oval, somewhat 

 irregular in outline ; calicular fossae deep ; columella spongy, with a flat upper surface, 

 not projecting into the calice. Five cycles of septa ; the primaries and secondaries 

 subequal, not exsert, with nearly vertical inner edges. The quaternaries are united 

 with the tertiaries near the columella ; the fifth cycle is complete except in the lateral 

 systems, and the quinary septa unite with the quaternaries high up in the calice ; the 

 lower orders of septa fenestrate with serrated or denticulated margins. Costse fine, of 

 equal size, extending to the base of the stem. 



Height of colony 27 millims. , the largest calice measures 15 millims. x 11 millims. ; 

 depth of calice 7 millims. ; smallest calice 11 millims. x 8 millims. 



A single specimen from deep water off Galle. 



