134 MADEEPOEAEIA. 



134. Madrepora cxmeata. 



Madrepora cuneata, Dana, Zoophytes, p. 487 ; M.-Edwards & Haime, Coralliaires, t. iii. p. 161 ; Quelch, 

 ' Challenger' Keef-Corals, pp. 148 & 149 ; Eathbun, Proc. U.S. Nat. Mus. 1887, vol. x. p. 15. 



Corallum incrusting and spreading^ with a few distinct, erect, short, contorted plates 

 2 to 3 cm. long and 3 to 5 cm. broad. Corallites at the apex as in other species, about 3 mm. 

 diameter; walls confluent. Radial corallites crowded, tubular, with moderately thick wall, 

 generally almost at right angles, varying from subimmersed to 2 mm. in length ; diameter 

 1*5 to 2 mm. On some specimens there are short isolated proliferations at intervals, each 

 with a large central corallite similar in all respects to those at the margin of the plates. 

 Primary septa short, secondaries scarcely noticeable. Wall and coenenchyma covered with 

 closely packed, blunt, spinose plates. 



The specimens from the Capricorn Islands form an interesting series, which illustrate the 

 variety in colony-formation. The youngest specimen consists of an incrusting saucer-shaped 

 plate with an incurved margin, and without erect plates arising from its surface, but the 

 larger (axial) corallites, from which 'such plates would in time have been formed, are clearly 

 indicated. The * Challenger' specimen is a portion of a similar colony. The next specimen 

 in the series has an incrusting plate-like base, from which narrow erect plates arise to a 

 height of 6 to 10 cm. ; these are 12 cm. broad and 1 to 2 cm. thick. The corallites on the 

 outer surface of the erect plates are not all of the radial type ; some of them already indicate 

 new outgrowths, and these form irregular longitudinal corrugations on the surface. Finally, 

 the largest specimen is without the incrusting base ; the erect plates are 16 cm. high, and 

 are provided with prominent longitudinal ridges, which in turn have irregular prominences 

 on the surface. 



Pacific Ocean : Fiji and Great-Barrier Reef. 



a, ^. Fiji. H.M.S.' Challenger.' 86.12.9.246. 



c. Capricorn Islands. J. B. Jukes, Esq. [P.]. 46. 7. 30. 33. 



d-i. Capricorn Islands. Saville-Kent Coll. 92. 6. 8. 43 to 47. 



?j-l. Rocky Island. ' Saville-Kent Coll. 93. 6. 8. 258 to 260. 



135. Madrepora plicata. (Plate IX. fig. D.) 



Madrepora plicata, Brook, Ann. Mag. N. H. 1891, vol. viii. p. 465. 



Madrepora incrugtans, Rehberg, Abb. naturw. Ver. Hamburg, 1892, Bd. xii. p. 35. 



Corallum consisting of broad oblique plates from a common base. The plates are about 

 8 cm. long and 4 to 9 cm. broad near the apex, narrower below, and 1 cm. thick. Each plate 

 bears one or more prominent longitudinal ridges on its surface. Each ridge bears a number 

 of rosettes of corallites, the central corallite in each being rather larger than the others, thus 

 indicating an approach to branch-formation with its accompanying enlarged terminal (parent) 

 corallite. Corallites at the apices of the plates tubular, 2 mm. in diameter, slightly promi- 

 nent ; wall thick and porous. Radial coralhtes tubular and appressed above, shorter and 



