MATTHAI— RECENT COLONIAL ASTR^IDiE 49 



1848. Echinopora (pars), Dana, Expl. exp. Zooph., p. 277. 



1850. Astrea (pars), Milne Edwards and Haime, Ann. Sci. Nat., Zool., 3'= ser., xii, p. 97. 



1850. Echinopora (pars), Milne Edwards and Haime, Ann. Sci. Nat., Zool., 3" s^r., xii, p. 621. 



1857. ffeliastrcea (pars), Milne Edwards and Haime, Hist. Nat. Corall., ii, p. 456. 



1857. Echinopora (pars), Milne Edwards and Haime, Hist. Nat. Corall., ii, p. 621. 



1879. Orbicella (pars), Klunzinger, Korall. Roth. Meer., iii, p. 47. 



1879. Echinopora, Klunzinger, Korall. Roth. Meer., iii, p. 54. 



1884. Echinopora, Duncan, Journ. Linn. Sec. London, Zool., xviii, p. 117. 



1889. Echinopora, Ortmann, Steinkorall. Slid. Ceylons, Zool. Jahrb., iv, p. 530. 



1904. Echinopora (pars), Gardiner, Fauna Geogr. Maldives and Laocadives, p. 782. 



Corallum. Varying considerably, flat, thin and foliaceous to massive, and rising 

 into branching hillocks. Peritheca vesicular or dense, the vesicles being often filled up, 

 usually with upright spinulate echinulations arranged in rows connecting costse of neigh- 

 bouring corallites, their bases often fused to form ridges which are specially distinct 

 towards edges where spines are small or absent. Corallites round or oval, close or quite 

 separated, level or projecting up to a height of 6 mm., usually one side more than the other, 

 near the edges of corallum the sides facing same not projecting at all. Calices not deep, 

 sometimes almost flat. Septa from 3 — 5 orders, side spinulose, exsert up to 2 mm., on 

 edges confluent with perithecal costae. Paliform lobes present or absent. Costse always 

 present, varying in thickness, usually with upright spines. Often the last order of septa 

 distinguishable only in costse. Columella spongy, formed of trabeculse from septal 

 margins. 



Polyps. Circular or oval ; when corallites project, edge-zones cover their entire free 

 surface ; coenosarcal regions usually extensive, varying in width up to 6 mm. Mesenteries 

 in three cycles, 6, 6 and 12 couples, last sometimes incomplete, pi'imaries meeting stomo- 

 dseum, all with fllaments. Tentacles entoccelic and exocoelic, but number always equalling 

 that of the entocoeles and exocoeles, each with a large knobbed terminal battery and from 

 three to six smaller sub-terminal ones. Stomodseum usually laterally compressed, with two 

 directive grooves. Nematocysts III uniformly modified into the III b type in all polyps 

 examined ; nematocysts II with the dark-stained axis extending to even more than two- 

 thirds length of sac. Tentacular endoderm much thickened owing to vacuolation and 

 ~ somewhat lobulated, the protoplasm being reduced to thin strands, appearing transparent 

 owing to scarcity of algse. 



Multiplication by budding, usually from coenosarc, sometimes from edge-zone. 



Verrill rightly separated U. aspera, Ed. and H., from Echinopora, and established a 

 new genus, Trachypora, for it. Klunzinger later substituted Echinophyllia for this genus. 

 In Lamarck's collection in the Paris Museum there are two specimens from the Indian 

 Ocean named E. aspera by Milne Edwards and Haime, which obviously were Lamarck's 

 originals of Explanaria aspera ; these resemble Mycedium okeni, Ed. and H. (Fungidse), 

 of which there are two large examples in the Pai-is Museum. I have not been able to see 

 Klunzinger's example of Echinophyllia aspera, but from his figure it appears to be a near 

 relative of E. aspera, Ed. and H., though not quite identical with it. 



Gardiner's small figured type of E. magna has a thicker facies than E. aspera, 

 Ed. and H., resembling Milne Edwards and Haime's larger example of Mycedium okeni. 



Distribution. Red Sea, Indian and Pacific Oceans. 

 SECOND SERIES— ZOOLOGY, VOL. XVII. 7 



