106 MADREPORARIA. 
prominent septa. Lower down the corallites become thickened, verruciform, or immersed. 
Corallum very porous and reticulate in section; surface openly reticulate; wall striato- 
reticulate, echinulate near the base. 
Mauritius. 
a. Mauritius. Purchased. 78. 2.4.7. (Type.) 
99. Madrepora anthocercis. (Plate XIII. fig. C.) 
Madrepora coronata, Brook (non Rehberg), Ann. Mag. N. H. 1892, vol. x. p. 456. 
Corallum cespitose or, in large specimens, forming broad much-flattened clumps from an 
incrusting base ; diameter 20 to 24 cm., height 6 cm., base 12 cm. diameter. Branches short, 
crowded, acervate, undivided, excepting near the margin, often broader at the apex than the 
base owing to the acervate condition and the presence of elongate corallites at and round the 
apex ; length 1-2 to 3cm., or more in the case of marginal branches ; diameter 5 to 7 mm. at 
the base, frequently 1 em. or more at the apex; apices a little over 1 em. apart. Axial 
corallites cylindrical, 2 or more frequently 3 mm. diameter and about 4 mm. exsert ; wall 
porous and strongly striate ; star well-developed but deep. The apex of a branch is rarely 
simple, usually two or more corallites surrounding the axial corallite increase in size so as to 
be indistinguishable from it—indeed, in certain cases the parent corallite becomes almost 
obliterated by the formation of stout proliferous corallites around it. Radial corallites rela- 
tively large, ascending, but with wide aperture, wall rather thin, margin often horizontal ; the 
form is variable, nariform at first, but with increase in size dimidiate, tubular or funnel- 
shaped ; length 2 to 4 mm., diameter 1:5 to 2°5 mm.; those near the apex are crowded, those 
lower down are rather distant and less prominent. Star of the radial corallites moderately 
developed, the directive septa distinctly broader and stouter than the others. Corallum 
porous ; surface covered with strongly dentate plates ; wall deeply striate and echinulate. 
Pacific Ocean : Great Barrier Reef area. 
a. Palm Island. Saville-Kent Coll. 92. 6. 8. 235. T 
b,c. Rocky Island. Saville-Kent Coll. 92. 6. 8. 236 & 7. } Bass? 
100. Madrepora recumbens. (Plate XXVII. fig. F.) 
Madrepora recumbens, Brook, Ann. Mag. N. H. 1892, vol. x. p. 461. 
Corallum cespitose at first, becoming flattened, frondose or semivasiform with increase in 
size; largest specimen 30 cm. broad. Proximal portion of main divisions fused into a solid 
plate without branchlets on the outer surface, but with small scattered immersed corallites ; 
distal parts more or less confluent; many of the corallites are nariform or subtubular, but do 
not form projecting twigs. Branchlets on the upper surface short, subconical and somewhat 
arcuate, 1 to 2:5 cm. long, 8 to 13 mm. diameter at the base, rapidly tapering, and usually 
simple. Where the outline of the main divisions is distinguishable the branchlets are seen to 
be arranged in a single row on the upper surface of each branch, with immersed cells in the 
lines of fusion between adjoining branches. Apices usually about 1:2 cm. apart, but some- 
