196 MADREPORARIA. 
SPECIES INCERTZ SEDIS. 
213. Madrepora coronata. 
Madrepora coronata, Rehberg, Abhand. nat. Ver. Hamburg, 1892, Bd. xii. p. 38, pl. iv. figs. 6 & 7 (non 
Brook, Ann. Mag. N. H. 1892, vol. x. p. 456). 
Corallum flattened corymbiform and pedicellate. Horizontal branches broad and plate- 
like, with small lateral twigs, which are also flattened and provided with short, subimmersed 
or immersed corallites ; the upper surface of these branches is rounded and, in the middle of 
the colony, provided only with immersed corallites. Towards the periphery arched branchlets 
arise on the upper surface, which are 10 to 20 em. long and provided with lateral twigs, all 
of which reach one plane. The corallites are rather distant and attain a maximum length of 
3 mm., but gradually become immersed below ; the inner part of the wall is absent, only the 
bud-corallites of terminal twigs have a complete tubular wall, and the wall is then thicker. 
Surface openly striate or tabulato-echinulate, wall rather closely striate. The largest 
specimen is 1 m. in diameter. Young colonies do not show well the characteristic flattened 
horizontal branches. (Rehderg.) 
Nossibé, Madagascar (Hamburg Museum). 
214. Madrepora dichotoma. 
Madrepora dichotoma, Rehberg, Abhand. nat. Ver. Hamburg, 1892, Bd. xii. p. 39, pl. ii. figs. 15 & 17. 
The colony arises from a solid style-like base, with chiefly dichotomous branches on its 
upper surface. The branches arise separately from the base. The outer ones have regularly 
arranged twigs on the outer surface as in M. aculeus, Dana. Towards the centre the bud- 
twigs gradually become less numerous and many of the apices are simple. Corallites rather 
distant, of medium size, strongly nariform and bent at the apex. Axial corallites only a 
little larger than the radial ones, cylindrical and prominent. Surface tabulato-echinulate. 
In corallites with an elongate aperture the lower directive septum is very broad. Immersed 
corallites scattered towards the middle of the branches, but very numerous below. Colony 
25 to 30 cm. diameter and about 20 cm. high. Branches not over i em. thick. (Rehberg.) 
Pelew Islands (Hamburg Museum). 
215. Madrepora gonagra. 
Madrepora gonagra, M.-Edwards & Haime, Coralliaires, t. iii. p. 151 (? non Briiggemann, Abh. nat. Ver. 
Bremen, 1877, Bd. v. p. 898; non Briiggemann, Phil. Trans. 1879, vol. clxviil. p. 575). 
Corallum forming cespitose tufts, resembling those of M. plantaginea, but having short 
rounded corallites grouped irregularly, so as to appear like nodosities ; aperture of the coral- 
lites remarkably small. (M.-Edwards & H.) 
