1900.] MARINE FAUNA OF CHRISTMAS ISLAND. 125 



In its explanate growth this is not unlike G. plcmulata of 

 Milne-Edwards & Haime, from some unknown locality, but the 

 calicles in that species are 7-8 mm. across, sometimes lengthening 

 to 15 mm. before dividing, This is the second explanate species 

 of Goniastrcea which has been recorded, although it may be 

 remarked by the way that the diagnosis of the genus is not so 

 clear as might be, and it is not always easy to distinguish between 

 Goniastrcea and Prionastrcea (cf. Klunzinger, op. cit. vol. iii. 1879). 



In pools and channels in reef-flat, Flying Fish Cove. 



Genus (?) CAULASTRiEA. 



A few very varying fragments in spirit which appear to come 

 between Mussa and Caulastrcea. There is a single flabellate 

 corallite (4*5 cm. long by 3-5 broad) which has died down, and 

 from its fossa 3 new ones of different lengths and sizes have budded 

 out. In addition there are two long (6 cm.) tapering corallites, 

 with points free but fused near their rims, below which a bunch 

 of (9) small buds project, curving upwards ; below the bunch there 

 are places where single buds have been broken off. There are two 

 of these detached young corallites, which are very like single 

 corallites of Galaceea, smooth below, ribbed above, and slightly 

 curved. The variations among these small fragments are thus so 

 great, that more material is necessary before any accurate account 

 of the coral can be given, or its position in the system determined. 



Genus Galaxea Oken. 

 Gal axe a aspera Quelch. 



Galaxea aspera Quelch, Chall. Eep. xvi. (1886) p. 72, pi. 4. 

 figs. 5-5 d. 



There is a dried specimen with a single loose corallite and a 

 much finer specimen in good preservation in spirit. The latter 

 shows the budding of the corallites above the level of the 

 perithecal tissue. The specimens seem to agree in all ascertainable 

 particulars with Mr. Quelch's species, viz., in their long projecting 

 corallites, the septal formula, the pronounced costse, and the dense 

 perithecal tissue. As far as I have been able to ascertain, the 

 locality nearest to the Keeling- Cocos group from which Galaxea 

 has been recorded is the Straits of Sunda ; but the specimen from 

 that locality was referred by Milne-Edwards and Haime (see 

 Galaxea ellisi, Les Cor. ii. p. 228) to the coral figured by Ellis 

 (Phil. Trans, liii. 1764, pi. 20), which is quite different to this. 



Pools in reef-flat, Flying-Fish Cove. 



Genus Mussa Oken. 

 Mussa. (?) regalis Dana. 



Mussa (?) regalis Dana, Zoophytes, 1848, p. 182, pi. 8. fig. 5. 

 Two fragments of a meandrine Mussa. The fragments are 

 chips from the ridges between adjoining calicles. In the smaller 



