MADREPORA. 109 
The three ‘ Challenger’ specimens referred by Quelch to M. hyacinthus, M. conferta, 
and M. vastula appear to me to belong to one species, and differ chiefly in the shape of the 
vase or plate. All agree in the characters of the under surface, which supply the chief 
distinction from M. hyacinthus, Dana. The specimen referred to M. hyacinthus by Quelch 
differs from the other two in having usually shorter and more proliferous branchlets on the 
upper surface, but especially in the axial corallites, many of which are slightly over 2 mm. 
diameter, with a wide shallow cup. 
Indo-Pacific Ocean : Tongatabu, Fiji Islands, Great-Barrier Reef, Torres Straits, Ami- 
rante Islands, ? Rodriguez. 
a. Reefs, Fiji. H.M.S. ‘Challenger.’ 85. 2.1.12. (Type.) 
6. Kandavu, Fiji. H.M.S. ‘Challenger.? 85. 2.1.17. (Type of M. vastula, 
Quelch.) 
c. Levuka, Fiji. H.M.S. ‘Challenger’ 85. 2.1. 2 (=WM. hyacinthus, 
Quelch.) 
d. Tongatabu. J.J. Lister, Esq. [P.]. 91. 3.6.17. (Young colony.) 
e,f. Eagle Island, Amirante H.M.S. ‘ Alert” 82. 10. 17. 141 & 185. 
Islands: 10 fathoms. 
g,. Rocky Island. Saville-Kent Coll. 92. 6. 8. 149 & 264. 
i-k, Cleremont Island. Saville-Kent Coll. 92. 6. 8. 150 to 152 
1. Thursday Island. Sayille-Kent Coll. 92. 6. 8. 265. (Var.) 
?m. Rodriguez. Royal Society [P.]. 76. 5. 5. 99. (=WM. microcladus, 
Brigg.) 
103. Madrepora delicatula. (Plate XXVIII. figs. D & E.) 
Madrepora delicatula, Brook, Ann. Mag. N. H. 1891, vol. vii. p. 461. 
Corallum yvasiform or extending horizontally; branches not over 8 mm. thick, laxly 
coalescent, but not complanate, and bearing on the under surface numerous slender branchlets 
almost at right angles, 1 em. or more in length and generally 2:5 mm. diameter at the base, 
provided with distant, appressed tubular buds ; appressed tubular and immersed corallites also 
occur between the twigs. The upper surface bears slender arcuate branches, not over 5 mm. 
thick, which give rise to delicate ascending branchlets, singly or in groups of two or three ; these 
are 1°5 to 2°5 em. long and scarcely 3 mm. thick at the base, apparently tapering, owing to 
the radial corallites being shorter near the apex. Axial corallites 1:5 mm. diameter, usually 
9-5 mm. exsert. Radial corallites rather distant, round-nariform, or labellate, 1 to 1°3 mm. 
wide and 1 to 4 mm. long; the lip of the more elongate ones is frequently a little incurved ; 
wall thin, aperture round, star indistinct. Corallum very porous and fragile; surface 
vermiculato-echinulate ; wall finely striate, echinulate near the base. 
Solomon Islands. 
a. Treasury Island, Solomon Islands. Dr. Guppy [P.]. 84. 12. 11. 23. (Type.) 
6. Port Denison. Saville-Kent Coll. 92. 6. 8. 148. 
Q 
