MADEEPORA. 113 



often divided above into two or four branchlets, many of which, especially near the centre of 

 the corallum, bear numerous ascending proliferations. Axial corallites 2"5 to 3 mm. diameter, 

 rarely more than 1 mm. exsert, margin scarcely rounded. The central branchlets bear 

 crowded proliferations, 7 mm. long and 4 mm. thick, with crowded immersed corallites 

 between; others are dimidiate and appressed, 25 to 4 mm. long and I'o mm. thick ; wall thin 

 but firm. The peripheral branchlets have few proliferous corallites; most are subequal, 

 nariform with an elongate lip, and a little compressed, 3 mm. long and 1*3 mm. thick. Star 

 moderately prominent, the directive septa very broad. Corallum rather porous ; surface 

 finely echinulate ; wall striato-echiuulate. 



Mauritius. 

 a. Mauritius. Purchased. 78. 2. 4. 6. (Type.) 



109. Madrepora indica. (Plate XXXIV. fig. A.) 



Corallum cespitose, subcorymbose, or consisting of a cluster of slender suberect 

 branches from an oblique base. Diameter of the colony about 17 cm., height 14 cm. The 

 base may be broad or narrow. Branches over 1 cm. diameter near the base, divided into 

 two or more branchlets often at about the same point, each again forked and often proliferous 

 near the apex ; distal divisions 2 to 4 cm. long and 6 mm. thick, but the thickness is variable 

 — in one specimen only 5 mm., xa another a few of the branchlets are 10 mm. in diameter. 

 Axial corallites cylindrical, 2 to 2'5, rarely 3 mm. diameter; primary septa equal and well 

 developed ; in corallites of 3 mm. diameter a narrow second cycle is also present. The 

 radial corallites are nearly all immersed except on the distal divisions, and sometimes also on 

 the basal parts of these; the promiaent corallites are crowded, more or less appressed, 

 nariform, half-tubular or sublabellate, somewhat compressed near the apex of a branchlet, 

 becoming short, firm-walled, and more open below. Stouter branched specimens have the 

 corallite wall thicker than in other cases, and many of the smaller corallites between them 

 have a spiniform wall. In one specimen the corallites are mostly of one type ; in another, with 

 slender branchlets, some of the corallites remain more or less prominent nearly to the base 

 of the branchlets. In the prominent corallites the septa are imperfectly developed ; usually 

 only the directives are recognizable, and the outer one is a little broader than the inner. In 

 the immersed corallites the primary septa are narrow and subequal, but the directives are 

 stouter than the others ; sometimes a more or less complete second cycle is present. 

 Corallum porous ; surface covered with spinose plates ; wall usually fragile, strongly striate, 

 echinulate at the base. 



Indian Ocean. 



a-c. Ramesvaram. Madras Mus. 88. 11. 25. 13 j 93. 4. 7. 138 & 139. (Types.) 



