60 THE VOYAGE OF H.M.S. CHALLENGER. 
much divided and subdivaricate, especially at the outer parts; branchlets somewhat 
smaller than the branches, rather short and subacute, not winged at apex. Calicles 
generally crowded, rather shallow, quite small, about 0°5 or 0°75 mm. in diameter, regularly 
circular, irregularly placed, but often distinctly seriate near the apical parts, where the 
upper wall is generally rather arched and prominent ; throughout the greater part of the 
corallum, especially towards the apical parts, the whole margin of the calicle is distinctly 
raised and rimmed, owing to the prominence and regularity of the marginal spinules, 
sixteen to twenty-four in number, which are often broad and septiform, and in the case 
of the larger ones are continuous with the septa which are developed within the calicle. 
Septa, generally six, extremely well developed at the sides and upper portion of the cup, 
but not distinct at the bottom of the fossa, broad, thickened and exsert, placed regularly 
apart with equal or subequal interseptal spaces; in many calicles two additional septa 
are present, situated one in each of the distal lateral chambers, but these septa are 
always very small and rudimentary. Columella conspicuous, compressed, narrow, 
styliform and pointed, projecting nearly to the margin. The two lateral pits are rather 
small and extremely deep, situated midway between the proximal and distal’ margin of 
the calicle. Texture compact; surface spinulose, the spinules being rather short and 
acute, though often thickened and long. 
The thick and strong branches, the shallow calicles and subexsert columella, the 
ereat development of the prominent septa, together with the raised continuous marginal 
rim to the calicles will readily mark the species, which has much of the general habit of 
Stylophora subseriata, while in essential characters it seems to be allied to the fossil 
species, Stylophora costulata. : 
A single specimen was collected. 
Locality.—Reefs, Fiji. 
8. Seriatopora ocellata, Ehrenberg. 
Seriatopora ocellata, Ehrenberg, Cor. roth. Meer., p. 122. 
os »,  Milne-Edwards and Haime, Cor., i. p. 313. 
5 », Studer, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1878, p. 540, pl. iii. 
fig. 10. 
Two very fine and interesting specimens of this species were collected. In essential 
characters they agree in every respect, but the habit of growth differs considerably. In 
one the branches are much divided and coalescent at very short intervals, so that the 
clump becomes close and intricate ; while in the other the branches are less divided and 
more elongated, coalescent at longer intervals, the aspect of the clump becoming more 
loose and elevated. The species is quite distinct from Seriatopora spinosa. The cells 
are very large and open, and at the base they are in indistinct series and are separated 
