136 THE VOYAGE OF H.M.S. CHALLENGER. 
very small ones, which are only distinct quite at the margin, where they are separated by 
long slits; the surface below is very slightly perforated, having a very dense and smooth 
appearance, especially at the centre, which is very sparsely marked with small costal 
spines (probably much enlarged in old specimens); the spines on the costee are very 
irregular, crowded, ragged, elongated, often 5 mm. or more in length, bent or contorted, 
and often clustered and divided ; they are slender or thickened, not sharp, but more or less 
divided at the apex into numerous fine, irregular spinules, which are also sparsely placed 
throughout the length of the spines and are faintly visible to the naked eye. Seven cycles 
of septa complete, an eighth more or less incomplete. The septa are rather thin, unequally 
thickened at the central part, becoming nearly equal at the margin and more or less 
equally raised, except those of the last cycles; the primaries and secondaries equal, very 
suddenly thickened near the inner margin, where those of opposite sides are closely 
approximated, so as nearly to touch above ; the tertiaries nearly as large. The teeth of 
the septa are peculiar; the margin of the free border of the septa is shghtly wavy, and 
the teeth appear as the projecting ends of opposite lateral thickenings, which are 
continued downwards on the face of the septa for about 3 or 4mm. Except on the last 
cycle, the teeth are subequal, crowded, somewhat irregular, rather short, small and acute, 
but finely pointed, bemg broader across than in the direction of the septa. Fossa 
elongated, narrow above, but rather wide below, owing to the crescentic shape of the 
septal ends ; columella rudimentary. 
This species is very distinctly marked both by the characters of its costae and of its 
septa. The waviness and plication of the margins of the septa recall the structure often 
seen in delicate specimens of Fungia patella, while the nature of the teeth brings to 
mind Fungia scrwposa. The costal characters resemble those of Fungia horrida in 
many respects. 
Two specimens were obtained, which are from about 10 to 11 em. in diameter. 
Locality.—Tahiti. 
10. Fungia plana, Studer. 
Fungia plana, Studer, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1877, p. 650, pl. iv. 
fig. 15. 
A single specimen of this species was obtained. It is somewhat elongated and quite 
flattened. The species is extremely close to the Fungia serrulata, Verrill, and probably it 
is not distinct from it. 
Locality.— Banda. 
