MADREPORA. 143 
near the base of the branches give the species a general resemblance to M. scherzeriana, 
but the corallites are of quite a different type. In immature specimens the prominent radial 
corallites have not quite such a thick wall, and the proliferations near the base of the 
branches are neither so numerous nor so well marked. 
Pacific Ocean : Fiji, Great-Barrier Reef, Torres Straits, Arafura Sea. 
a-c. Rocky Island. Saville-Kent Coll. 92.6. 8.114 to 116. (Types.) 
d. Rocky Island. Saville-Kent Coll. 92. 6. 8. 117. 
e. Capricorn Islands. Saville-Kent Coll. 92.6.8. 118. 
f. Kandavu, Fiji. H.M.S. ‘ Challenger.’ 86. 12. 9. 289. 
(=U. seriata, Quelch.) 
g. Thursday Island. Saville-Kent Coll. 92. 6. 8. 119. 
h-j. Rocky Island. Saville-Kent Coll. 92. 6. 8. 123,125 & 126. 
k. Capricorn Islands. Saville-Kent Coll. 92. 6. 8. 298. 
?7. Evans Bank, Arafura Sea. H.M.S. ‘Penguin. 92. 4. 5. 5. 
147. Madrepora samoensis. (Plate VI. fig. C and Plate XXXI. fig. A.) 
Madrepora samoensis, Brook, Ann. Mag. N. H. vol. 1891, viii. p. 468. 
Corallum cespitose from a broad, rounded, incrusting base; height of corallum 24 em., 
breadth 28em. Branches very stout and much divided. The main branches usually become 
divided into 8 or 10 secondary ascending branches, which increase in length towards the 
centre of the corallum ; the outer ones are 3 to 5 cm. long, the inner ones 12 or 13 em. ; 
these branches are often 2 cm. thick, not terete, but owing to crowding they are more or 
less angular im section ; the secondary branches bear a third series of ascending branchlets, 
2 to 6 em. long and 1 em. thick, those directed outwards being longest and most numerous. 
All the divisions are only slightly tapermg and have a blunt apex. Axial corallites 3 mm. 
diameter, or less in the case of the smaller subdivisions, scarcely exsert ; wall thick, very 
porous, margin rounded. Star very distinct, the primary septa often nearly meet in the 
middle line, but in the smaller corallites the directives are largest ; a second cycle is also 
moderately developed. Around the axial corallites the radial corallites are frequently 
arranged in subregular longitudinal rows. The radial corallites are nariform or short 
tubular at first, with the inner part of the wall more or less incomplete, the outer part 
thickened and very porous; they are 2 to 3 mm. long and about 2 mm. diameter. Rows of 
smaller, subimmersed corallites are situated between the prominent ones, but the linear 
arrangement is lost 3 to 5 cm. from the apex. At a point about 2 cm. from the apex the 
prominent corallites become more thickened and bear buds; they are then about 4 mm. long 
and nearly 3 mm. diameter. Such proliferous corallites occur at intervals of 5 to 8 mm. 
over the whole of the upper part of the corallum; a few become more elongate and may 
attain a length of 2cm. At a point varying from 2°5 to 6 cm. from the apex of a branch or 
branchlet the whole of the corallites become short, and on the inner side of the branches 
almost all of them are immersed. The star of the radial corallites not destined to form 
u 2 
