MADEEPOEA. 



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 diflfer 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 hy 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. 



H.M.S. ' Challenger.' 

 H.M.S. ' Challenger.' 



Quelch.) 

 H.M.S. 'Challenger.' 



Quelch.) 

 J. J. Lister, Esq. [P.] 

 H.M.S. ' Alert.' 82. 



85. 2. 1. 12. 

 85. 2. 1. 17. 



(Type.) 



(Type of M. vastula. 



85. 2. 1. 2. {= M. hyacinthus, 



. 91. 3. 6. 17. (Young colony.) 

 10. 17. 141 & 135. 



Saville-Kent Coll. 92. 6. 8. 149 & 264. 

 Savillc-Kent Coll. 92. 6. 8. 150 to 152. . 

 Saville-Keut Coll. 92. 6. 8. 265. (Var.) 

 Royal Society [P.]. 76. 5. 5. 99. { = M. microcladus, 

 Briigg.) 



103. Madrepora deUcatula. (Plate XXVIII. figs. D & E.) 



Madrepora deUcatula, Brook, Ann. Mag. N. H. 1891, vol. viii. p. 461. 



Corallum vasiform 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 cm. 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 15 to 2*5 cm. 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 

 2'5 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. 



Treasury Island, Solomon Islands. 

 Port Denison. 



Dr. Guppy [P.]. 84. 12. 11. 23. (Type.) 

 Saville-Kent Coll. 92. 6. 8. 148. 



