MATTHAI— RECENT COLONIAL ASTR^ID^ 121 



ridges are thicker than broad with nematocysts I present in their lower halves, these 

 occurring also in the mesenterial filaments. Nematocysts II c are arranged close together 

 as in G. solida. Nematocysts 'III are absent. The endoderm is somewhat swollen on either 

 side of the thickened region of the mesenterial mesoglsea, with few algse. 



In one of the polyps sectioned two stomodsea are present with six couples of 

 mesenteries attached to each. The appearance suggests that one has been formed as an 

 upward diverticulum from the base of the other, since the former opens into the latter and 

 some of the original principal mesenteries are still found passing from one to the other. 

 This polyp recalls some of the figures which Duerden has given of transverse sections 

 of polyps of West Indian Acropora (Madrepora ; 33, figs. 4, 5 and 7), but he interprets 

 those appearances on the hypothesis of stomodseal fission. 



B. Corallum. Ehrenberg's specimen of Astrcea pectinata [ = G. pectinata, Klunz.) 

 in the Berlin Museum measures 8"5 x 6 x 5'5 cm., but has somewhat narrower corallites 

 than my examples. In the Paris Museum G. quoyi, Ed. and H., is represented by a 

 specimen from Tongatabou, measuring 11x11x7 cm., and G. grayi, Ed. and H., by a 

 smaller example from Australasia. Klunzinger has rightly referred two of Milne Edwards 

 and Haime's specimens to G. pectinata, one from Red Sea originally assigned to G. solida 

 and another without locality to Prionastrcea seycheUensis, Ed. and H. In the Hof- 

 museum, Vienna, are two fine specimens collected by the " Pola " exhibition, one from 

 Idda and the other (larger, 17x11x14 cm.), from Bernice, referred by Marenzeller to 

 G. pectinata. 



Quelch's new species G. coronalis is founded on a small, thin, somewhat convex edge- 

 piece from Banda, measuring 8x8 cm. ; it is, in all probability, the same as G. pectinata, 

 the only diflFerences being that the columellae are somewhat better developed and the 

 paliform lobes broader. The two specimens (one, large, from Somerset, Cape York, the 

 other, small, from Banda), referred by Quelch to G. quoyi, differ from Milne Edwards and 

 Haime's examples of the same species in that (l) the columellse are composed of closely- 

 twisted trabeculse, and (2) the septa are somewhat sloping, very narrow at the calicular 

 margins, about 18 meeting columella. The two small specimens from Mactan Island, 

 Philippines, which the same author has referred to G. grayi, resemble his specimens of 

 G. quoyi, but have slightly larger and deeper calices. 



Localities. Red Sea (4). Chagos, Salomon (l). Also from Tongatabou and 

 Australasia (Milne Edwards and Haime), ? Banda (Quelch), French Somaliland (Vaughan). 



4. GoNiASTREA PLANULdTA, Milne Edwards and Haime. (PI. 28, fig. 5 ; 31, figs. 7 

 and 8.) 



1850. Goniastrea planulata, Milne Edwards and Haime, Ann. Sci. Nat., ZooL, Z" ser., xii, p. 162. 

 1857. 6 oniastrcea planulata, Milne Edwards and Haime, Hist. Nat. CoralL, ii, p. 447. 

 1904. Goniastrma pectinata, Gardiner, Fauna Geogr. Maldives and Laccadives, p. 773. 



Corallum. Incrusting, becoming massive. Corallites with tendency to meander as 

 in G. pectinata. Inter-calicinal walls thicker, up to 3 mm., usually about 1'5 mm., ridged. 

 Single calices somewhat smaller, 5 — 6 X 4 mm. (the longest meandering calyx without any 

 mark of fission 11 mm.), depth about 5 mm. 



Septa vertical, of equal width at calicular margins, but thicker and arranged closer 

 SECOND SERIES— ZOOLOGY, VOL. XVII. 16 



