460 Mr. G. Brook on new Species of 



at an acute angle wliicli may be 20 centim. long and 1-5 

 centim. thick, spreading out laterally, their subdivisions sub- 

 alternate and confluent, the whole habit recalling the espalier 

 form of fruit-tree ; a few very short branchlets arise obliquely 

 from the anterior surface, but the majority conform to the 

 general plane of growth. Apical corallites 2 to 2"5 millim. 

 diameter, tubular, scarcely exsert, wall not specially thick- 

 ened, and closely resembling the lateral ones except in shape. 

 Lateral corallites on the anterior surface subequal, very 

 spreading, boat-shaped, nariform, or labellate, the aperture 

 wide and elongate, the upper margin almost at right angles to 

 the branch, the lower more or less convex ; wall thickened, 

 apex often a little hooked ; 2*5 millim. long and about 2 

 millim. thick. The corallites become a little less prominent 

 towards the base of the corallum, but immersed corallites are 

 practically absent. On the inferior surface the corallites are 

 more scattered and irregularly arranged, many open down- 

 wards, the majority are appressed, tubular, with only the 

 outer part of the wall free. A few immersed corallites occur, 

 but they are neither numerous nor generally distributed. 

 Corallum moderately porons, reticulate in section, anterior 

 surface subreticulate and echinulate, posterior surface dense 

 and finely echinulate, wall finely striate and echinulate. The 

 lateral corallites have six very narrow equal septa, with occa- 

 sionally indications of a second series. 

 Indian Ocean ; Seychelles. 



Madrepora concinna. 



Corallum corymbose, 30 centim. broad and 12 centim. high, 

 from a central base, scarcely pedicellate. Under surface of 

 the branches horizontal, much flattened, more or less con- 

 fluent, 9 centim. long and 2 centim. broad, provided with 

 irregular verruciform and lateral, elongate, tubular or conical 

 corallites ; immersed ones almost absent. Branches on the 

 upper surface 5 to 6 centim. long, 8 to 13 millim. thick, very 

 proliferous. Apical corallites 3*5 millim. diameter at the 

 base, tapering, 3 millim. exsert. Lateral corallites very 

 unequal; those at the apex are very short, small and thin- 

 walled, others immediately below tubo-nariform or tubular, 

 with a round or oblique aperture, frequently opening inwards ; 

 some are 3 to 6 millim. long and 2 to 3 millim. in diameter, 

 s[)reading, but not at right angles, wall tiiiek, margin rounded ; 

 others between are shorter or subimmersed; all are short or 

 subimniersed at the base of the brandies. Star not prominent, 

 consisting of narrow directive septa and four others which are 



