SS 
“| 
Tl 
MADREPORA. 131 
specimen from Rodriguez in which the cones are not present; but as in consequence the 
specific characters are not yet developed, the identity is uncertain. 
Indian Ocean: Rodriguez; ? Great-Barrier Reef. 
a, 6. Rodriguez. Royal Society [P.]. 76.5.5.93& 119. (Types.) 
c. Capricorn Islands. Saville-Kent Coll. 92. 6. 8. 49, 
Diviston II. 
5. Subgenus ISOPORA. 
Astrea (part.), Lamarck. 
Isopora, Studer, MB. Akad. Wiss. Berlin, 1878, p. 535. 
Corallum cormiform, consisting of several thick, blunt, plate-like branches from a 
common base. The axial corallites are differently arranged to those in all other divisions of 
the genus Madrepora. Usually each axial (parent) corallite forms the axis of a branch or 
branchlet, and they therefore occur singly. In this subgenus they do not occur singly in 
typical cases, but a considerable number of closely-arranged parent corallites occupy the 
centre of each plate, and may be recognized at the margin by their circular wall and central 
aperture. They are quite normal in form; it is only the fact that they are collected into 
groups corresponding with the thickness and breadth of the plates that has led to their being 
overlooked. Radial corallites usually thick-walled, tubular, or cochleariform. 
This subgenus corresponds with Dana’s Section G of the genus Madrepora. 
A. Corallites cochleariform, with thick outer and thin, more or less incomplete, inner wall. 
131. Madrepora palifera. 
Astrea palifera, Lamarck, Hist. Anim. sans Vert. t. ii. p. 262; ed. 2, p. 409; Lamouroux, Encycl. 
p. 180. 
? Gemmipora palifera, Blainyille (non Dana &e.), Manuel d’Actin. p. 387. 
Madrepora labrosa, Dana, Zoophytes, p. 486, pl. xliii. fig. 3, pl. xxxi. fig. 10; M.-Edwards & Haime, 
Coralliaires, t. iii. p. 161; Rathbun, Proc. U.S. Nat. Mus. 1887, vol. x. p. 16; B.-Smith, Ann. 
Mag. N. H. 1890, vol. vi. p. 455. 
Isopora labrosa, Studer, MB. Akad. Wiss. Berlin, 1878, p. 535. 
Corallum laminate, plates erect or spreading, obtuse, 2 to 8 em. broad and 1°5 to 4 cm. 
thick, margin rounded, apex blunt and usually flattened. Corallites at the apex tubular, but 
usually not prominent, 3 mm. diameter. Walls very porous, 1 mm. thick or more, and 
frequently confluent. There are two cycles of septa present, both rather narrow, but the direc- 
tives are thicker than the others. Radial corallites cochleariform or tubular, with incomplete 
