82 
TRIBE III.— MADREPORACEA. 
i 
fifths of a line broad ; other calicles labellate, fragile, lip broad and elongated, j 
much flattened ; star distinct, 6-rayed, two lamellae broader than the others. l 
Singapore, East Indies. — Exp. Exp , 
15. Madrepora aculeus (Dana). — Prostrate, branches stout (1-3 inches 
thick), and very uneven, very much and very closely subdivided; below, 
branchlets short, angular, horizontal, and covered with long tubular calicles ; 
above, branchlets erect, and rising with a curve, very crowded, angular, and 
attenuated, 2 lines thick, and often 2 inches long, subacute. Corallum with 
the apicle calicle prominent (often a line) ; the lateral not crovrded, small, 
round-nariform, with the edge thin ; cell round, opening upward, star mostly 
distinct, two of the lamellae a little the broadest, 
Plate 32, fig. 6, part of corallum, natural size; 6a, branchlet, ditto; 6 6, 
profile of calicles. — Feejee Islands. — Exp. Exp. 
16. Madrepora tenuis (Z>awa).— Cespitose, rounded, sparingly spread- i 
ing; branchlets very slender, scarcely 2 lines thick, 3 inches long, subterete 
and proliferous. Corallum with the apical calicle small (|- of a line broad), a | 
little prominent ; the lateral appressed tubiform, irregular, elongate (1^ lines) j 
and slender ; margin fragile, exterior neatly striate and finely scabrous ; aper- 
ture circular, star indistinct, two lamellas a little prominent. 
17. Madrepora tubicinaria {Dana). — Cespitose, rounded, branches but 
little spreading, closely ramose, branchlets very nearly terete, 3 to 4 lines 
stout, scarcely at all tapering, apex obtuse. Corallum quite porous ; apical 
calicles very stout (1 to 1^ lines broad), a little prominent; the lateral, ap- 
pressed tubiform, and regular, four-fifths of a line broad and li to 2 lines long, ' 
thin and fragile at the margin, exterior neatly striate, aperture broad and cir- 
cular, opening upward; star short six-rayed. 
Plate 32, fig. 7, corallum, natural size ; 7 a, extremity of branch, natural 
size. — Feejee Islands. — Exp. Exp. 
18. Madrepora paxilligera {Dana). — Very broad, pedicellate cespitose, 
plane above; base of the frond solid, disk-form, stout; below, scarcely con- 
vex, naked, pedicellate at middle; above, branchlets digitiform, 2h to 3 inches 
long, and i to f of an inch thick, erect and subterete, rarely furcate, subacute ; 
margin of the corallum squarrose, the branchlets being very short and incipi- 
ent. Corallum having the apical calicle short and small (hardly a line broad) : 
the lateral a little unequal, very crowded, a little prominent, compressed nari- 
form, or sometimes dimidiate, striate, aperture oblong, star scarcely distinct. 
Plate 34, fig. 1, part of corallum, natural size; 2a, part of branchlet, ditto; 
1 6, profile of calicles, ditto. — Tahiti, Society Islands. — Exp. Exp. 
19. Madrepora nasdta {Dana). — Broad cespitose, short pedicellate, a 
little convex, with a solid plano-obconical base ; below, complanate and nearly 
