182 THE VOYAGE OF H.M.S. CHALLENGER. 
Specimens of this species were found with Porites superficialis, forming bright 
yellow, or whitish-pink, rounded masses in the rock pools. 
Locality.—St. Vincent, Cape Verde Islands. 
8. Porites superficialis, Duchassaing and Michelotti. 
Porites superficialis, Duchassaing and Michelotti, Mém. Cor. des Antilles, p. 82. 
Neoporites michelint, Duchassaing and Michelotti, Suppl. Mém. Cor. des Antilles, p, 98., pl. x. 
figs. 9, 10. 
A single specimen of this species was obtained. It forms a small, convex, slightly 
irregular mass incrusting a nodule of calcareous matter. Of the two species which I have 
placed together, there does not seem to be any marked character which is not common 
to both as described by Duchassaing and Michelotti. The very small calicles are 
specially noticed under Porites (Neoporites) michelini, but this is a most inconstant 
character in these massive and incrusting species, and at different parts of the same 
specimen very different measurements can be obtained, depending not only upon the 
simple size of the calicles, but also on their distance from each other. 
Locality.—St. Vincent, Cape Verde Islands. 
9. Porites astreoides, Lamarck. 
Porites astreoides, Lamarck, Hist. Anim. sans Vert., ii. p. 269, 1816. 
A specimen of this very common West Indian species was obtained. Very good 
figures of the species are given in the Report on the Florida Reefs, pl. xvi. 
Locality.—St. Thomas. 
10. Porites crassistellata, n. sp. (Pl. XI. figs. 4-4). 
Corallum incrusting at the base, massive, gibbous, unevenly and unequally mam- 
millate. Calicles very uneven, subcircular or angular, rather deep but often very shallow, 
rather large, about 2mm. wide, often less, arranged either in series along raised, ridge-like 
projections and m corresponding depressions, or scattered irregularly, many being much 
raised above surrounding ones ; walls very thick, angular, unequally raised and thickened, 
having at times the appearance of tubercles between the cups; by the development 
of young calicles on the raised, thickened portions of the wall, the surface becomes very 
uneven, and often ridged ; septa rough, unequal, thick, often united within, but scarcely 
prominent on the upper part of the wall. Interseptal spaces very narrow and slit-like. 
Pali from six to eight, thick and blunt, distinct and long in a few cups, but generally 
1 Moseley, Notes by a Naturalist on the Challenger, p. 48. 
