110 MADEEPOEAEIA. 



104. Madrepora kenti. (Plate XI. fig. B.) 



Madrepora henti. Brook, Ann. Mag. N. H. 1892, vol. x. p. 458. 



Corallum horizontal or corymbose, in either case the main branches are divided into two 

 Bubparallel series of branches ; the upper series bear branchlets on the superior surface and 

 the lower series bear branchlets which are almost equally important on the inferior surface ; 

 the main branches are 2 to 2*5 cm. thick. The inferior series of branchlets in the horizontal 

 form extend obliquely forwards, and are 3*5 to 5 cm. long and 5 to 7 mm. thick at the base, 

 simple or proliferous at the apex ; the apices are nearly all arranged in one plane. Coral- 

 lites large, yery distant, round, appressed tubiform ; inner part of the wall not free in the 

 shorter corallites, but more or less prominent in the more elongate ones ; length of the outer 

 part of the wall 2 to 4 mm., diameter 2*5 mm., aperture 1'5 mm. The radial corallites are 

 longest near the apex of a branchlet and gradually decrease in length towards the base; 

 scarcely any are completely immersed. The branchlets on the upper surface are similar to 

 those below but less oblique ; length 35 to 6 cm., diameter at the base 7 to 10 mm., the 

 more slender ones are scarcely tapering. Axial corallites 2*5 to 3 mm. diameter, cylindrical, 

 margin plane, aperture 1*5 mm. Radial corallites appressed tubular, similar to those below 

 but more crowded and more prominent; the majority have the outer part of the wall 

 produced into a rounded lip (ligulate), but the inner part is usually not free ; length 3 to 

 4 mm., diameter 25 mm. across the lip, but usually rather narrower at the base ; in most 

 cases the corallites are almost as prominent just above the base of a branchlet as near the 

 apex. Star moderately developed, the two directive septa prominent, the other primaries of 

 medium breadth, and frequently a narrow second cycle is also present. Corallum moderately 

 porous in section, but dense and pitted at the surface, echinulate ; wall striato-reticulate, 

 echinulate at the base. 



The corymbose variety has more crowded and clustered branchlets ; on the upper surface 

 two or three often spring from the same stalk, but the same bifarious condition of the 

 branches and branchlets occurs as in the horizontal form. The outer part of the wall of the 

 radial corallites is here not quite so spreading, and the inner part of the wall is rarely 

 prominent except in corallites which become proliferous. 



Pacific Ocean : Torres Straits; Great-Barrier Reef. 



a. Thursday Island. Saville-Kent Coll. 92. 6. 8. 202. (Horizontal.) 



b. Low Woody Island. Saville-Kent Coll. 29. 6. 8. 203. (Corymbose 



;)}Type 



105. Madrepora bifaria. (Plate XXX. fig. A.) 

 Madrepora bifaria, Brook, Ann. Mag. N. H. 1892, vol. x. p. 453. 



Corallum horizontal, with numerous erect spiciform branchlets on the under surface 

 similar to those above. Colony 30 cm. long, 23 cm. broad, and 12 cm. thick. Main 



