REPORT ON THE REEF-CORALS. 173 
This species, though agreeing in general habit with Montipora palmata, differs 
markedly in the nature of its surface, which brings it into close relation with Montipora 
poritiformis, Montipora digitata and Montipora tortuosa. A variety occurs on the 
Fiji Reefs which is very close to Montipora digitata, but differs in its much more 
compressed branches, and in its cells, which are not sunk towards the extremities of the 
branches in large depressions, so as to give a pitted appearance to the surface. The 
presence of large, pit-like depressions, in which the calicles are situated, forms an essential 
character of each cell of Montipora digitata, as described by Dana. 
Localities.—Banda ; reefs, Fiji. 
5. Montipora rigida, Verrill. 
Montipora rigida, Verrill, Proc. Essex Inst., vol. v. part 3, p. 26 
A very interesting specimen of this species was obtained. The ccenenchyma is very 
firm, but at the extremities of the well-developed branches and branchlets it becomes very 
loose and porous, and almost fragile. The calicles of the basal parts are as described by 
Verrill, but they are easily abraded, and thus become even with the surface. At the 
apical parts they are not prominent, but are surrounded by a thin, scarcely raised line. 
Briiggemann has referred this species to Montipora (Madrepora) limitata, Ellis and 
Solander, but the identification seems to me doubtful. 
Locality— Mactan Island, Philippines. 
6. Montipora irregularis, u. sp. (Pl. VIII. figs. 4-4). 
Corallam incrusting and spreading at the base, forming thick, irregular, nodular pro- 
cesses above, which develop into much divided branches. Branches thick, closely placed, 
ascending, often coalescent, and becoming broad and almost palmated ; very unequal in 
length and thickness, compressed, subterete or nearly round, never angular. Branchlets 
about 12 mm. thick, sometimes compressed, generally rounded, scarcely elongated, and 
tapering slightly to an obtuse apex. Calicles quite immersed, rather large, about 1 mm. 
wide, slightly larger on the prominent parts, very crowded, separated by spaces generally 
much narrower than their diameter, very deep. Septa of two cycles, unequal, rather 
prominent, and very thin. Ccenenchyma, extremely porous; surface furnished neither 
with papillae nor tubercles, but having the narrow intercalicinal spaces delicately 
echinulate. 
This species has many points of resemblance both with Montipora divaricata, Briig- 
gemann, and with Montipora digitata (Dana), but can be readily distinguished from 
both of these forms. 
Locality. Samboangan, Philippines. 
