122 PERCY SLADEN TRUST EXPEDITION 



togethei' than in G. pectinata, edges serrate, sides with crowded pointed spinules, total 

 number 22 — 29, usually continuous from corallite to corallite ; 9 — 11 septa meeting 

 columella, with conspicuous paliform lobes ('75 — 1 mm. broad). Columella somewhat 

 better developed than in G. pectinata. 



Towards edges calices shallower, but septa and inter-calicinal walls thinner. 



A thicker and rougher species than G. pectinata, but polyps necessary for determining 

 whether it is different from the latter or not*. Milne Edwards and Haime's type of 

 G. planulata (locality unknown) is 13 cm. long and 10 cm. broad, with incrusting corallum, 

 but somewhat shallower calices than in my specimens (PI. 31, fig. 7). 



Localities. Maldives : (1 dredged) ; Goidu (l) ; Turadu (l). Chagos : Salomon (3) ; 

 Egmont (2). Red Sea (1). Not recorded from the Pacific Ocean. 



ADDENDA. SOME TYPE SPECIMENS. 



Astrcea deformis, Ehrb., CoralL, p. 96 (non Astrea deformis, Lam.). 



Prionastrcea seychellensis, Ed. and H., Corall. ii, p. 517. 



I have examined Ehrenberg's large type of Astrcea deformis and Milne Edwards and 

 Haime's two large examples of Prionastrcea seychellensis f , and have no doubt that they 

 belong to the same species. There is also a large series of this species from different 

 localities in my collections showing a wide and interesting range of skeletal variation. 

 I hope to receive polyps of this important species in a short time, when a full account 

 of its hard and soft parts will be given. At present it cannot be settled whether the 

 species is a Favia or Goniastrea — probably the latter. 



lAPEJiASTBEA (Milne Edwards and Haime). 

 'i. Apheastrjsa deformis (Lamarck). 



1816. Astrea deformis, Lamarck, Hist. Anim. sans vert., ii, p. 264 ; 2' edit., p. 414. 



1830. Dipsastrea deformis, Blainville, Diet. Sci. Nat., Ix, p. 338; Manuel d'Actinol, p. 273. 



1849. Aphrastrea deformis, Milne Edwards and Haime, Ann. Sci. Nat., Zool., 3^ser., x, pi. 9, fig. 11, and 12, p. 165. 



1857. Aphrastrcea deformis, Milne Edwards and Haime, Hist. Nat. CoralL, ii, p. 452. 



1904. Aphrastrcea deformis, Gardiner, Fauna Geogr. Maldives and Laccadives, ii, p. 773, pi. 63, fig. 31. 



The four specimens from the Maldives, referred by Gardiner to Aphrastrcea deformis 

 (Lam.), are identical with Milne Edwards and Haime's figure of the species, the type being 

 missing from the Paris Museum. No polyps of this species were available for examina- 

 tion, but from the appearance of the corallites it may well be presumed that the species 

 does not possess the bilateral symmetry characteristic of Group I. The question whether 

 it constitutes a separate genus or is to be placed in the genus Favia can be settled only 

 after a study of its polyps. 



The principal characters of Gardiner's specimens are as follows : Corallum more or less 

 flat. Corallites penta- or hexagonal, more or less uniform in size. Inter-calicinal walls, 

 much thickened, up to 5 or 6 mm., average 3 mm. ; this thickness due to secondary 

 deposition of calcareous material in the form of vesicles within the corallites t filling up 



* Three sectioned polyps of this species from a specimen from Maldives were useless for histological purposes. 



t The intra-corallite deposition of calcareous matter is very evident in transverse sections of the corallum 

 and is much more than the inter-corallite deposit {i.e. peritheca). The significance of this phenomenon can be 

 determined only after examining the polyps. 



