194 MADREPORARTA. 
together than is usually the case. Corallum very dense ; surface subrugose and very finely 
echinulate ; wall striate and finely echinulate. - 
China Sea. 
a. Macclesfield Bank, 37 fath. H.M.S. ‘ Penguin” 92.10.17. 33. hn 
b. Macclesfield Bank, 31 fath. H.M.S. ‘Penguin.’ 92.10.17. 34. J ~YPE: 
210. Madrepora inermis. (Plate XXIX. figs. A, B.) 
Madrepora inermis, Brook, Ann. Mag. N. H. 1891, vol. viii. p. 462. 
Corallum consisting of slender laxly-divided branches, which probably extend subhori- 
zontally. The branches are about 21 em. long and 8 mm. thick, somewhat flattened in places 
and completely or almost completely devoid of corallites on the under surface, forked and 
divaricately branched; the branchlets are sublateral, 1-5 to 6 cm. long, 4 to 5 mm, thick, 
scarcely tapering, those under 5 em. in length are usually simple. In addition to the more 
noticeable branchlets, there are a few short, lateral, subalternate ramiculi on the stouter 
branchlets at intervals of about 1 cm., they are 4 to 8 mm. long and 3 mm. thick. Axial 
corallites 2 mm. diameter, 1 mm. exsert, wall scarcely thickened, with a star of 6 well-deve- 
loped septa and sometimes traces of a second cycle. Radial corallites very short, spreading 
tubular, rather distant, often with indications of a subspiral arrangement; length 1 to 2 mm. ; 
diameter the same, but usually 1°5 mm., and the base may be dilated; those near the apex of 
a branchlet are not so spreading, but the aperture is always rounded; the longest ones are 
lateral in position and, on becoming proliferous, give rise to the short ramiculi already referred 
to. Immersed corallites are practically absent. Wall thin but firm; the septa are arranged 
in a single cycle, the lower directive often much broader than the others. Corallum very 
dense ; surface dense, smooth on the underside, slightly rough but not spmose on the anterior 
surface of the stouter branches. The wall of the axial and younger radial corallites is roughly 
costulate and the striations are continued to the ccenenchyma, but below the striations are 
lost on the corallites as well as on the general surface. 
South Seas. 
a, 6. South Seas. Purchased. 41.12.11.6 & 7. (Types.) 
211. Madrepora parilis. 
Madrepora parilis, Quelch, ‘ Challenger’ Reef Corals, p. 162, pl. ix. fig. 3. 
Corallum spreading more or less horizontally, the branches and branchlets developing 
continuously in one plane from opposite sides of the larger branches, and nearly of equal size 
throughout, viz. 5 to 7 mm. thick. Branches round or vertically compressed, closely placed, 
rarely coalescent, although extending nearly at right angles. Axial corallites cylindrical, 2 to 
3 mm. diameter, with moderately thick and porous wall, not rounded at the margin ; the star 
consists of 12 septa, the directives broadest. The radial corallites are wide apart, tubular, 
