172 THE VOYAGE OF H.M.S. CHALLENGER. 
coalescent, sometimes rounded ; branchlets short, somewhat thinner than the branches, 
generally much compressed, sometimes terete and tapering. Calicles very small and 
immersed, about 0°25 mm. wide, not crowded, scarcely conspicuous between the close and 
long papille of the surface. Septa unequal, six being distinct, the secondaries rudimentary. 
Ceenenchyma very light and porous, widely reticulate above, becoming less porous below ; 
surface covered by long very crowded papille, which at the basal part of the corallum 
are short, unequal, generally rounded, about the same size as the cups, and closely 
crowded by minute spinules, while at the distal part they are very elongated, thinner, and 
somewhat raggedly divided into spinules. 
This species is close to Montipora palmata, but is distinguished by its lighter and 
more porous structure, by the much smaller and less crowded calicles, and by the much 
more densely papillose nature of the surface, the papille being much more elongated 
and ragged, especially towards the distal parts. 
Locality. —Banda. 
3. Montipora rubra (Quoy and Gaimard). 
Alveopora rubra, Quoy and Gaimard, Voy. de l’Astrol., Zooph., p. 242, pl. xix. figs. 11-14. 
Montipora rubra, Milne-Edwards and Haime, Cor., iii. p. 209. 
Several small specimens were obtained which seem referable to this species. The 
corallum, especially at the basal parts, is compressed, becoming subterete and attenuated 
above, though often rounded at the end. The surface is destitute of spinules or tubercles, 
but is rendered very uneven owing to the slightly raised, outer borders of the deeply 
placed calicles, which are thus surrounded by small, and rather fragile, subpolygonal or 
subcircular projections. 
Montipora poritiformis, Verrill, is very close to this species, but apparently is separated 
by its round branches, and the less-developed projections around the calicles. 
Locality.—Reefs, Fiji. 
4, Montipora levis, n. sp. (Pl. VIII. figs. 2-20). 
Corallum small, ramose; branches about 7 mm. thick, much compressed and coalescent, 
forming broad, palmated expansions, sometimes subterete ; branchlets somewhat thinner 
than the branches, subterete and generally acuminate, rather short, often compressed. 
Calicles immersed, small and crowded, from about 0°25 to 0°5 mm. wide, and from 1 to 
1°25 mm. apart. Septa very thin, the primaries conspicuous and broad, the secondaries 
very small. Coenenchyma .finely porous, becoming dense below. Surface very finely 
spinulose or granulated, reticulate and even, sometimes slightly roughened, never 
papillose nor tuberculate. 
