MADEEPOEA. 37 



12. Madrepora vasiformis. (Plate XXVI. fig. A.) 



Madrepora flabelliformis, Briiggemann (non M.-Edwards & Haime), Phil. Trans. 1879, vol. olxviii. 

 p. 575. 



Corallum shallow, solid, vasiform, 28 cm. diameter, 10 cm. high ; attachment ohiique. 

 The under surface is quite solid, excepting towards the margin of the colony, where the 

 outline of the branches is indicated by narrow fissures. The whole under surface is devoid 

 of branchlets, and is covered with crowded suberect tubular corallites; some are sub- 

 immersed, with rather thin wall, but the majority have the wall thick and the margin 

 rounded, many have the wall much dilated ; length 1 to 3 mm., diameter 1 to 3 mm., according 

 to the thickness of the wall ; the directive septa are often the only ones recognizable, but in 

 other cases the primary series may be more or less complete. The upper surface of the vase 

 consists of numerous short subconical twigs, which arise obliquely from the main branches ; 

 their apices arc about 1'5 cm. apart, length 1'5 to 3 cm., diameter at the base 8 to 12 mm., 

 those near the margin of the vase are closely applied to the main divisions. Axial corallites 

 cylindrical, 2 to 2'5 mm. diameter ; the primary septa almost meet in the middle line, but 

 the directives are slightly broader; a second cycle is not recognizable. Radial corallites 

 crowded, spreading, very unequal, and of variable form ; the largest are thick- walled, tubular, 

 with the inner part of the wall often incomplete, margin slightly rounded, wall porous ; such 

 corallites may bear one or two very small buds on the outer surface ; length 3 mm., diameter 

 1-8 mm.; others between are nariform, dimidiate, or labellate, with the wall of variable 

 thickness, many towards the base are subimmersed. In the tubular corallites the star 

 consists of 6 septa, the directives, and especially the outer one, most prominent. All the 

 septa are very narrow in the subimmersed corallites, often only the directives are 

 recognizable. Corallum moderately porous, wall striato-echinulate. 



In habit the species closely resembles M. efflorescens, but the absence of a second cycle 

 of septa iu the axial corallites renders it uncertain whether it really belongs to the same 



subgenus. 



Rodriguez, 

 a. Rodriguez. Royal Society [P.]. 76.5.5.92. (Type = M./«6e//t/omt», Briigg.) 



13. Madrepora orbicularis. (Plate II.) 



Madrepora efflorescens, Ortmann (non Dana), Zool. JB. 1889, Bd. iv. p. 511; ?ibid. 1888, Bd. iii. 



p. 153. 

 Madreiiora orbicularis. Brook, Ann. Mag. N. H. 1892, vol. x. p. 460. 



Corallum disk-shaped, 50 cm. broad and 4-5 cm. thick near the margin, thicker in the 

 central part, with numerous irregular prominences. On the under surface the branches are 

 fused into an almost solid plate, almost plane iu some parts, but in others with irregular 



a 



