MADEEPOEA. 147 



k. Thursday Island. Saville-Kent Coll. 92. 6. 8. 122. 



/. Rocky Island. Saville-Kent Coll. 92. 6. 8. 277. 



Var. uncinata. 



a,b. Singapore. Mus. Comp. Zool. Harvard Coll. 91. 6. 16. 



1 &2. 

 c. Wreck Bay, Great-Barrier Reef. J. B. Jukes, Esq. [P.]. 46. 7. 30. 26, 



?«?. Tizard Bank. H.M.S. 'Rambler.' 89.9.24.100. 



{ = M. scabrosa, B.-Sm.) 



151. Madrepora ortmanni. 



Madrepora crassa, Ortmann {non Edwards & Haime), Zool. JB. 1888, Bd. iii. p. 149. 



Corallum subarborescent, the divisions very stout. Branches 10 cm. long and 3 cm. 

 thick, bearing 4 or 5 thick digitif'orm branchlets nearly 2 cm. thick ; in certain cases, owing 

 apparently to the fusion of two branches, they form oval spreading lobes 8 cm. long, 3"5 cm. 

 broad, and 2 cm. thick, the apex oval, 2 cm. by 1 cm., with 2 axial corallites separated by 

 others of the radial type. Here, as in M. brueggemanni, there is, in certain branches, an 

 approach to the condition of the subgenus Isopora. Axial corallites 4 mm. diameter, little 

 exsert ; wall rounded, with a large aperture (2 mm.) and deep-seated star of 12 septa. Radial 

 corallites long, appressed, tubular, crowded, and markedly imbricate, but in some parts more 

 spreading and irregular; diameter 25 to 3 mm., length up to 6 mm., or even more; wall 

 moderately thick, aperture large, margin rounded. The star consists of 6 well-developed 

 septa, and of a more or less complete second cycle. Corallum dense, but still reticulate in 

 section ; surface reticulate, with a spongy film in places ; wall finely echinulate, not striate, 

 echinulations longer near the base of the corallites. 



Pacific Ocean : Ponape and Bowen, Queensland {Strassburg Museum). 



152. Madrepora acervata. 



Madrepora acervata, Dana {non Verrill), Zoophytes, p. 460, pi. xxxiv. fig. 4 ; M.-Edwards & Haime, 

 Coralliaircs, t. iii. p. 154 ; Ilathbun, Proc. F.S. Nat. Mus. 1887, vol. x. p. 12 {non Studer, 

 Mitth. naturf. Ges. Bern, 1880, p. 22 ; non B.-Smith, Ann. Mag. N. H. 1890, vol. vi. p. 454), 



Madrepora plantaginea, Verrill {non Lamarck, non Dana), BuU. Mus. Comp. Zool. 1864, vol. i. p. 42; 

 ibid. Appendix, 1875 ed. of Dana's Corals & Coral Islands, p. 333. 



Corallum broad, cespitose, a little convex above ; exterior branches nearly prostrate and 

 somewhat flattened below. Branchlets 5 cm. long and 1 to 1"6 cm. thick, very proliferous, 

 often acute at the apex and subretuse. Axial corallites broad, 3 to 4 mm., scarcely exsert ; 

 aperture scarcely one-fourth the diameter. Radial corallites crowded, appressed, tubiform, 

 2 to 3 mm. long; wall distinctly striated, oblique at the apex; lip thick; aperture elliptical; 

 star very distinct, the directive septa nearly meet below. {Dana.) 



Singapore. 



