106 MADREPOEAEIA. 



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 eoronata. Brook (won Kehberg), 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 3 cm., or more in the case of marginal branches ; diameter 5 to 7 mm. at 

 the base, frequently 1 cm. or more at the apex ; apices a little over 1 cm. 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. 



b, c. Rocky Island. Saville-Kent Coll. 92. 6. 8. 236 & 7. 



j Types. 



100. Madrepora recumbens. (Plate XXVII. fig. F.) 

 Madrepora recumbens, Brook, Ann. Mag. N. H. ] 892, 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 12 cm. apart, but some- 



