186 MADREPORARIA, 
divisions are simple or bear one, rarely two, short appressed tubular buds. The majority are 
15 mm, diameter, scarcely tapering, but the more elongate ones are thicker at the base; all 
are usually a little over 1 mm. diameter at the apex. Margin plane, aperture not contracted; 
the star consists of six well-developed septa, the directives being very frequently fused 
together in the middle line; wall rather thin but firm. Corallum dense and little porous, 
excepting near the apex of a colony; surface dense, pitted in parts, more or less strongly 
echinulate ; wall striate and echinulate, becoming finely echinulate below. The condition of 
the surface and the prominence or even the presence of striz on the wall vary considerably in 
different parts of the same specimen. The corallites on the stem and main branches are 
immersed, distant, 1 mm. diameter, with the directive septa usually fused together. 
I have compared the type of M. durvillei with what appear to me to be typical speci- 
mens of M. echinata, and have been unable to recognize any constant differences which can 
be considered of specific value. M.-Edwards’s figure of M. echinata is not typical, and 
probably should be referred to another species. As a variety, M. durvillei may be recognized 
by the following characters :—1. Ceenenchyma strongly striate and echinulate. 2. Star little 
developed in the immersed corallites. 3. The aperture of tubular corallites may be slightly 
contracted. 
Pacific Ocean: Fiji, Samoa, Australia, Sulu Sea, Sandwich Islands, Liu Kiu Islands. 
a. Australia. Sydney Museum. 84. 11. 25. 1. 
b,c. Pacific Ocean. G. Holsworth, Esq. [P.]. 91. 11.5.1 &2. 
d. ? Purchased. 43. 3. 6. 129. 
200. Madrepora subglabra. (Plate XXIX. fig. C.) 
Madrepora subglabra, Brook, Ann. Mag. N. H. 1891, vol. viii. p. 470. 
Madrepora echinata, Quelch, non Dana, ‘ Challenger’ Reef Corals, p. 162. 
Corallum extending in elongate, slender, and oblique or subprostrate branches, closely 
resembling M. procumbens in habit and in the form of the branchlets. Branches 6 to 18 em. 
long, 7 mm. diameter, not terete, owing to the swollen bases of the branchlets. Branchlets 
1 to 4 cm. long, similar to those of M. procumbens, but the corallites are more slender, 
scarcely over 1 mm. diameter at the apex; margin plane, aperture not contracted ; they vary 
from 4 to 15 mm. in length, the majority are about 7 mm. long, the terminal 8 or 4 mm. 
being free from budding corallites. The main branches bear a very small number of sub- 
immersed corallites about 0°7 mm. diameter. The star consists of six septa, the directives 
being thick and prominent, the others much narrower. Corallum dense; surface almost 
smooth, excepting near the apex, where it is finely echinulate; wall very finely striato- 
echinulate at first, the striz becoming lost later, and subsequently the echinulations as well. 
The ‘Challenger’ specimens referred by Quelch to M. echinata, together with another 
specimen in the Collection, appear to differ from the above in having a slightly more prostrate 
habit and in the presence of stronger echinulations ; but in these the echinulations are much 
finer and shorter on the inferior surface of the branches. 
