174 THE VOYAGE OF H.M.S. CHALLENGER. 
7. Montipora obtusata, u. sp. (Pl. VILL figs. 3-3). 
Corallum consisting of a broad, spreading, rather thin, and unevenly undulated plate, 
uniformly about 5 mm. thick, from the upper surface of which arise numerous short, 
thick, obtuse, sometimes subclavate, slightly compressed, irregular branches which may 
be as much as 2°5 em. long and 1 cm. thick, and may coalesce laterally to form thick 
masses. The edge of the plate is slightly turned up, rounded, and uniformly thick; the 
under surface is covered by a slight epitheca and incrusted by foreign matter almost to 
the margin where a few small calicles are found. Calicles small, about 0°5 mm. wide, 
immersed, never sunk in pits, but even with the surface, from about 1 to 2 mm. apart ; 
septa twelve, unequal, almost filling up the cavity of the cell, the secondaries often rudi- 
mentary. Ccenenchyma finely reticulate, but firm and rather dense; surface nearly 
smooth, very minutely spinulose, never papillose nor tubercular. 
The broad, spreading, basal plate, with the short, erect lobes or branches, the smooth 
surface, and the characters of the calicles, will readily serve to distinguish the species. 
Locality.— Reefs, Fiji. 
8. Montipora patula, Verrill. 
Montipora patula, Verrill, Proc. Essex Inst., vol. vi. p. 87. 
This species is represented by a very fine specimen, which at its centre incrusts 
dead branches of Madrepora, and has numerous short prominences on its upper surface 
due to the presence of parasitic growths. The cells are normally twelve-rayed, but in 
many parts, towards the edges of the corallum, the septa of the second cyele are quite 
rudimentary. 
Locality.—Amboina. 
9. Montipora exserta, n. sp. (Pl. VIII. figs. 5-5). 
Corallum forming a rather thin, flattened, broad, horizontal plate, about 8 mm. thick, 
lessening in thickness towards the edges, but never very thin, even close to the margin ; 
often incrusting foreign matter and thus becoming uneven. ‘The ccenenchyma is dense 
throughout and evenly reticulate, the surface appearing almost smooth, being very finely 
and minutely echinulate, never papillose nor tubercular. The under surface is covered to 
a short distance from the edge by a layer of rudimentary epitheca and foreign matter ; 
and where this is very thin or absent, the finely spinulose ccenenchyma, and small, 
immersed calicles, which are evenly and closely arranged throughout, are distinctly seen. 
On the upper surface the calicles are rather large, about 0°75 mm. in diameter, immersed, 
very regularly arranged, about 1 mm. apart or less. Septa twelve, the secondaries very 
small; two opposite primary septa much enlarged and exserted, so as to be easily seen 
