74 MADEEPOEAEIA. 



high; base 15 cm. diameter. The branches are about 1 cm. long and 1 to 1"3 cm. thick 

 near the centre of the colony, simple, bifid or trifid, with the subdivisions subparallel ; those 

 nearer the margin are shorter and more frequently subdivided ; the outer divisions of the 

 marginal branches extend horizontally, but are rarely 3 cm. long. Many of the apices bear 

 short proliferations. Axial corallites scarcely 2 mm. diameter, a little exsert, but provided 

 with bud-corallites almost to the margin. Radial corallites prominent and a little rounded, 

 if within 2 or 3 cm. of the summit, those below usually immersed or subimmersed ; pro- 

 minent corallites nariform, tubo-nariform, or dimidiate, sometimes in longitudinal rows, as 

 indicated by Dana, 2 to 3 mm. long, very spreading, about 1 mm, diameter; wall scarcely 

 thickened; aperture narrow and elongate. A few of the corallites near the summits are 

 stouter and more elongate, and indicate new proliferations. Star not well developed in the 

 prominent corallites, but more marked in those which are subimmersed or immersed. 

 Corallum rather porous above ; surface spongy echinulate ; wall finely striato-echinulate. 



Another specimen from the same locality has more proliferous branches and less 

 spreading corallites, which remain prominent to a greater distance from the summits than in 

 the specimen described above. 



Yar. crassilabia. 

 Corallum half corymbiform from a lateral attachment. Marginal branches subhori- 

 zontal, with numerous stout tubular corallites and short twigs, 7 to 14 mm. long, clothed 

 with subimmersed and immersed corallites. Upper surface with erect digitiform branchlets 

 about 1 cm. thick. Radial corallites prominent, nariform or dimidiate, spreading almost at 

 right angles, with thick dense wall and rounded margin ; a few short, nariform corallites 

 are scattered between the others; aperture oblique and elongate, length 2 to 3 mm., 

 diameter nearly 2 mm. ; the more prominent ones are arranged in longitudinal rows. The 

 corallites gradually become shorter towards the base of the branchlets, but scarcely any on 

 the superior surface of the corallum are completely immersed. It is possible that Dana's 

 figure represents a specimen with thick-waUed radial corallites. 



Pacific Ocean : Tahiti, Fiji, ? Capricorn Islands. 



a, b. Tahiti. H.M.S. 'Challenger.' 85. 2. 1. 5 & 85. 2. 1. 4. 



c. Fiji. F. M. Rayner, Esq. [P.]. 62. 2. 7. 1. (Var. crassilabia.) 



? d. Capricorn Islands. Saville-Kent Coll. 92. 6. 8. 303. 



60. Madrepora paxilligera. 



Madrepora paxiUigera, Dana Zoophytes, p. 452, pi. xxxiv. fig. 1 ; M.-Edwards & Haime, Coralliaires, 

 t. iii. p. 157 ; Yerrill, Bull. Mus. Comp. Zool. 1864, vol. i. p. 42 ; Duncan, Journ. Linn. Soc. 

 Lond. 1886, vol. xxi. p. 20; Eathbun, Proc. U.S. Nat. Mus. 1887, vol. x. p. 17; Ortmann, 

 Zool. JB. 1888, Bd. iii. p. 152 (non Quelch, ' Challenger ' Eeef Corals, p. 154 ; non B.-Smith, 

 Ann. Mag. N. H. 1890, vol. vi. p. 453). 



Dana gives the following particulars : — 



Corallum very broad, cespitose, pedicellate, plane above ; base of frond solid, disk-shaped. 



