MADREPORA. 81 
Radial corallites broad, tubo-nariform, short, widely open, wall striato-echinulate; septa in a 
single narrow cycle, the inner directive broadest. Axial corallites exsert, but scarcely larger 
than the radial ones. Corallum porous, reticulate in section ; surface reticulate or striate 
and echinulate. 
In the ‘Challenger’ specimen the small branchlets are seen to be produced from elongate 
tubular corallites, 2 mm. diameter near the apex, the terminal 4 to 6 mm. usually without 
buds. Radial corallites spreading, nariform or tubular, with the inner part of the wall 
scarcely free, 1:5 to 2 mm. wide, the outer part of the wall rarely 2mm. long; the aperture 
is wide and circular. Towards the base of the branches many of the corallites have a ring- 
shaped border, and in them a second cycle of septa is more or less completely represented. 
The species is closely related to M. tubigera. 
East Indies: Kingsmill Islands, Banda. 
a. Banda. H.M.S. ‘ Challenger.’ 86. 12. 9. 269. 
69. Madrepora dilatata. 
Madrepora tenuis, Ortmann (non Dana), Zool. JB. 1888, Bd. iii. p. 152. 
Corallum consisting of a bushy clump 10 cm. high and 16 cm. broad. Branches much 
divided from the base ; distal divisions 2 to 3 em. long and 4 to 5 mm. thick, often forked at 
the apex. Axial corallites 2 to 2:5 mm. thick, not over 2 mm. exsert: wall very porous and 
not much thickened. Radial corallites rather distant, elongate, appressed, tubular, with the 
distal part dilated and the aperture very oblique; the form is dimidiate, length 4 to 5 mm., 
diameter 2 mm., becoming short, and finally immersed below. Star well developed, but the 
septa are delicate. Corallum very porous; surface spongy and strongly echinulate ; wall 
very porous and striato-reticulate ; the stri are well marked, rather distant, and finely 
dentate. 
This species approaches M. tenuis, Dana, but differs from the specimens I have referred 
to that species in the stouter axial corallites, the more elongate and dilated radial corallites 
with very oblique aperture, and the better developed star. 
Pacific Ocean: Tongatabu (Strassburg Museum). 
70. Madrepora dendrum. (Plate XXXIII. figs. A, B.) 
Madrepora dendrum, B.-Smith, Ann. Mag. N. H. 1890, vol. vi. p. 452. 
Corallum “arborescent subcespitose; stem solid, strong; surface finely echinulato- 
striate, bearing curved, simple or proliferous, gradually tapering branchlets 2°5 cm. long and 
3 mm. thick, with compressed nariform calicles, tending to form into rows showing two very 
long (broad) septa; apical calicles 1 mm., exsert, stem distinct ; under surface shows branches 
sinuously curved, with spreading margin, not coalescing, with few immersed corallites.” (B.- 
Smith.) 
