MADEEPORA. 7S 



long ; aperture circular. Star very prominent in all the corallites ; the six primary septa 

 are subequal, and nearly meet in the middle line in the immersed corallites; in the pro- 

 minent ones the outer directive septum is rather broader than the others. 



A small number of immersed or subimmersed corallites have a greater diameter than 

 usual, and are provided with a third cycle of septa ; but, as in the case of M. mirahilis, the 

 calicles with three cycles of septa do not appear to have any constant position. The 

 corallum is porous and reticulate in section ; the surface is densely clothed with equal plate- 

 like echinulations ; wall more or less distinctly striate. 



a. China (probably South). Fisheries Exhibition. 84. 2. 26. 10. 



b. Korea Straits. J. F. R. Aylen, Esq., R.N. [P.]. 62. 7. 16. 33. 



c. Tsu-sima, Korea Straits. J. F. R. Aylen, Esq., R.N. [P.]. 62. 7. 16. 109. 





3. Subgenus POLYSTACHTS. 



Corallum cespitose, bushy or corymbose. Axial corallites cylindrical, little variable, 

 usually 2 to 2'5 mm. diameter, usually with a well-developed star of 12 septa. Branchlets 

 on the upper surface spiciform, with relatively large ascending corallites, in which rarely 

 more than the inner one-third of the wall is undeveloped. This subgenus is connected with 

 Lepidocyathus through M. frondosa and M. sinensis. 



A. Corallum cespilose, bushy or subcorymbose, but ahvays convex on the upper surface. 

 Corallites nariform to tubo-labellate or tubular ; wall not dense. 



a. Branches rarely under 1 cm. in thickness ; corallite-wall not fragile. 



59. Madrepora nasuta. 



Madrepora nasuia, Dana, Zoophytes, p. 453, pi. xxxiv. fig. 2 ; M. -Edwards & Haime, Coralliaires, t. iii. 

 p. 153; Verrill, Bull. Mus. Comp. Zool. 1864, vol. i. p. 42; ?Moseley, Proe. Roy. Soc. Lend. 

 1876, vol. xxiv. p. 549 ; Quelch, ' Challenger ' Reef Corals, p. 154 ; Rathbun, Proc. U.S. Nat. 

 Mus. 1887, vol. x. p. 16 (non B.-Smith, Ann. Mag. N. H. 1890, vol. vi. p. 453). 



Corallum broad cespitose, from a stout solid base, 15 cm. diameter in a specimen 

 30 cm. across; below complanate and nearly naked, stout pedicellate; above branchlets 

 crowded, digitiform, nearly simple, rarely proliferous, subterete, 5 to 6"25 cm. long and 

 8 to 10 mm. thick, subacute, branchlets of the margin horizontal and elongate. Radial 

 corallites very prominent, compressed-nariform, very finely striate ; aperture oblong. Star 

 often distinct, the directive septa a little the broadest. [Dana.) 



In the specimen figured the marginal branches do not appear either elongate or hori- 

 zontal, and the branches are less simple than one would suppose from the above description. 



One of the ' Challenger ' specimens referred by Quelch to this species agrees well with 

 Dana's figure, but not so exactly with the description. Corallum 30 cm. broad, 13 cm. 



