MADEEPOEA. 169 



corallites are chiefly ascending, and numerous small ones are scattered between those which are 

 most prominent. Star scarcely recognizable or not prominent. Corallum rather dense ; 

 surface reticulate and echinulate; wall striato-echinulate, but the striae become lost as the 

 wall increases in thickness. 



This species resembles M. australis in the form of the corallites. 



Indo-Pacific Ocean : Rodriguez, Great-Barrier Reef. 



a, b. Capricorn Islands. Saville-Kent Coll. 92. 6. 8. 285 & 286. 



c, d. Rodriguez. Royal Society [P.]. 76. 5. 5. 101 & 106, 



{= M. seriata, Briigg.) ^ Types. 



?e. Rodriguez. Royal Society [P.]. 76. 5. 5. 107. | 



(= M. haimei, Briigg., part.) J 



169. Madrepora leptocyathus. (Plate XVI. fig. C.) 



Madrepora leptocyathus, Brook, Ann. Mag. N. H. 1891, vol. viii. p. 463. 



Corallum flattened vasiform, from a broad base, not pedicellate. Marginal branches 

 oblique, fused into a solid plate below, excepting near the periphery, where they are a little 

 flattened and covered with short, crowded, appressed, tubular corallites with a thin wall. On 

 the upper surface all the branchlets rise from a solid base with very numerous immersed 

 corallites. The branchlets are about 3 cm. long and 1 to 1'4 cm. thick, frequently angular 

 below, but more tapering above; the apices are usually \'7 cm. apart. Those in the centre 

 are chiefly simple, but may bear a few proliferous corallites ; others, particularly near the 

 margin, are divided. Axial corallites 2'5 to 3 mm. diameter, cylindrical, scarcely exsert. 

 Radial corallites small, crowded, tubular or tubo-labellate, spreading at right angles, wall thin 

 and porous ; they are 1*5, rarely 2 mm. diameter, and seldom over 2*5 mm. long, a little 

 unequal, with small and delicate ones between. On the lower parts of the branchlets the 

 prominent corallites are not so numerous and the wall is thickened. Proliferous corallites 

 5 mm, long and 4 mm. wide (including the lateral buds). Star usually indistinct, but the 

 directive septa are sometimes prominent. Corallum rather dense ; snrface finely reticulate 

 and echinulate ; wall striato-echinulate. 



The type specimen appears to consist of two circular colonies fused together. 



Samoa. 

 a. Samoa. Rev. S. J. Whitmee [P.]. 75. 10. 2. 7. (Type.) 



170. Madrepora brevicollis. (Plate XXVIl. figs. A, B.) 

 Madrepora brevicollis. Brook, Ann. Mag. N. H. 1892, vol. x. p. 454. 



Corallum cespito-arborescent, or subcorymbosc and oblique ; branches 8 to 12 cm. long 

 in the bushy form, 1-5 cm. thick ; in oblique specimens the branches may be 22 cm. or more 

 in length, but do not increase correspondingly iu thickness. In bushy specimens the branches 



y2 



