MADREPORA. 37 
12. Madrepora vasiformis. (Plate XXVI. fig. A.) 
Madrepora flabelliformis, Briiggemann (non M.-Edwards & Haime), Phil. Trans. 1879, vol. elxviii. 
p. 575. 
Corallum shallow, solid, vasiform, 28 cm. diameter, 10 em. high; attachment oblique. 
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 8 mm., diameter | 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 are 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 inney 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 
18 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 in 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. flabelliformis, Briigg.) 
13. Madrepora orbicularis. (Plate II.) 
Madrepora efflorescens, Ortmann (non Dana), Zool. JB. 1889, Bd. iv. p. 511; ? ibid. 1888, Bd. iii. 
p. 153. 
Madrepora orbicularis, Brook, Ann. Mag. N. H. 1892, vol. x. p. 460. 
Corallum disk-shaped, 50 em. 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 in some parts, but in others with irregular 
G 
