MADEEPOEA. 35 



Corallum massive^ incrusting, forming broad arched plates with broad pyramidal or 

 conical elevations on the upper surface, and clustered ascending twigs towards the margin. 

 The cones are very unequal in size, 2*5 to 6'5 cm. in diameter at the base and 2 to 3"5 cm. 

 high. The axial corallites of the cones are only 2 to 2"5 mm. diameter, and scarcely exsert. 

 Short proliferous tubular corallites, not over 5 mm. long, are scattered irregularly over the 

 surface of the larger cones ; the radial corallites between them are short, tubular, with a more or 

 less oblique aperture, outer part of the wall thickened, the inner thin ; length 2 mm. or rather 

 more, diameter slightly under 2 mm. Such tubular corallites are about 3 to 5 mm. apart, 

 the interval between them is occupied by short nariform, subimmersed and small immersed 

 corallites. The star of the prominent corallites consists of well-developed directive septa 

 which nearly meet in the middle line, and of four other primaries together with part of a second 

 cycle, all o£ which are narrow and subequal, but the primary septa are stouter. The 

 marginal branches are 4 to 6 cm. long and about 6 to 12 mm. thick ; the stouter ones are 

 distinctly tapering. On these the axial corallites are hemispherical, 3 to 3"5 mm. diameter, 

 with a well-developed star of 12 septa. The radial corallites are chiefly gutter-shaped, but 

 with a variable number of short or immersed ones between ; length 2 to 3 mm., diameter 

 2 mm. at the apex, margin not rounded. The directive septa are prominent, the remaining 

 primaries narrow, and a second cycle is not developed. The form of the radial corallites of 

 the marginal branches resembles that of M. nobilis. 



China Sea. 



J3 



a, b. Tizard Bank, 2 fath. H.M.S. ' Rambler.' 89. 9. 24. 100 & 159. ( = M. pyra- 



midalis, B.-Sm.) 



c. Tizard Bank, 2 fath. H.M.S. 'Rambler.' 89. 9. 24. 98. { = M. seriata, B.- 



Sm.) ^^'I 



d. Tizard Bank, 1 fath. H.M.S. 'Rambler.' 89. 9. 24. 112. { = M. paxilUgera, 



B.-Sm.) 

 •? 93. 4. 7. 87. (Specimen figured.) 





B. Corallum consisting of horizontal or oblique radiating branches which ultimately become 

 fused into a disk-shaped plate or shallow vase, with numerous proliferous corallites on 

 the upper surface. 



11. Madrepora efflorescens. 



Madrepora efflorescens, Dana, Zoophytes, p. 441, pi. xxxiii. fig. 6; M.-Edwards & Haime, Coralliaires, 

 t. iii. p. 159 {non Ortmann, Zool. JB. 1888, Bd. ill. p. 153 ; ibid. 1889, Bd. iv. p. 511 ; non 

 B.-Smith, Ann. Mag. N. H. 1890, vol. vi. p. 454). 



Corallum vasiforra?, branches coalescing into a solid plate 12 to 18 mm. thick, 

 reticulate only at the margin and ribbed with the coalescing branches. Corallum flat below, 

 and having very short crowded branchlets above; the marginal ones 12 mm. long and 

 3 mm. diameter ; those near the middle of the colony not terete, 6 mm. long, acervate and 

 proliferous. Corallites on the under surface short; on the upper surface the branchlets 

 bear labellate corallites with long erect lip. Apical corallites cylindrical, 2 mm. long and 

 1 mm. broad. {Dana.) 



