MATTHAI— RECENT COLONIAL ASTR^ID^ 105 



1899. Orhicella heliopora, Gardiner, Proc. Zool. Soc. London, p. 756, pi. 49, fig. 4 (non Hdiastrcea heliopora, 



Milne Edwards and Haime). 

 1899. Orhicella solidior, Gardiner, Proc. Zool. Soc. London, p. 756 (non Hdiastrcea solidior, Milne Edwards 



and Haime). 

 1899. Orhicella funafutensis, Gardiner, Proc. Zool. Soc. London, p. 756, pi. 49, fig. 5. 



Corallum. Usually incrusting, sometimes massive. Corallites circular, oval or 

 sometimes laterally compressed, projecting up to 3"5 mm., usually 1'5 or 2 mm., in some 

 specimens with one side higher than the other as in F. doreyensis. Corallites usually 

 closely arranged but always with inter-corallite grooves, towards edges up to 3 mm. apart. 

 Calices about 4 — 5 mm. in diameter, when laterally compressed up to 8x5 mm., depth 

 3 — 5 mm. 



Septa thickening towards theca, vertical or slightly sloping, with toothed edges, 

 spinulose or coarsely rough sides, slightly exsert, 17 — 25 in number, 10 — 18 meeting 

 columella, each usually with a blunt paliform lobe and perforated behind it; 3 — 7 of the 

 principal septa, as a rule, somewhat broader, thicker and rougher than the others (the 

 degree of thickness varying in different examples), with conspicuous paliform lobes, and 

 exsert up to 1 or 1'5 mm. The subsidiary septa often curving towards and fusing with 

 sides of principals. Exsert ends of septa arched, rarely flat, serrate. An alternating 

 cycle of very narrow septa present, with smaller costse. Costse conspicuous, toothed, 

 usually meeting in inter-corallite grooves. Columella formed of septal trabeculse, varying 

 in degree of development, from -g- to -J width of calyx and from being loosely spongy to 

 compact. 



Multiplication by budding — the small corallites formed in this manner are found 

 intercalated between the ordinary ones — rarely also fission. 



Towards edges corallites are wider apart, up to 3 mm., and shallower. 



The skeletal facies of the present species has a general resemblance to that of 

 F. laxa. 



The polyps of this species were in a badly-preserved condition. In three polyps 

 sectioned (taken from a specimen from Rotuma resembling Gardiner's example of 

 Or&4ceZZa wa^ayaria) tentacles were present over all the entocceles and exocceles ; 8 — 10 

 couples of principal mesenteries and 11 — 14 subsidiaries were counted. Entocoelic pleats 

 were broader than in F. versipora and extended to about the middle of each principal 

 mesentery. 



It is likely that the present species may have been previously recorded by Dana, but 

 this point cannot be settled till Dana's Astreeid types are examined. A fairly large 

 specimen from Kandavu, Fiji, in the " Challenger " collection, which Quelch has referred 

 to Plesiastrcea indurata, Verrill, is identical . with Gardiner's examples of Orhicella 

 wahayana. 



Localities. Funafuti (8). Fiji, Wakaya (3). Eotuma (1). Known only from the 

 Pacific Ocean. 



14. Favia solidior (Milne Edwards and Haime). (PI. 25, fig. 8 ; 28, fig. 1.) 



1850. Astrea solidior, Milne Edwards and Haime, Ann. Sci. Nat., Zool., 3'^ ser., xii, p. 102. 

 1857. Heliastrcea solidior, Milne Edwards and Haime, Hist. Nat. CoralL, ii, p. 466. 



SECOND SERIES— ZOOLOGY, VOL. XVIL 14 



