30 
TRIBE I. ASTR^ACEA. 
Plate 11, fig. 5, polyps unexpanded, natural size ; 5 a, profile of the lamellae 
and ridges, natural size ; 5 &, same, enlarged ; 5 c, vertical section of corallum, 
natural size ; 5 rf, transverse section, natural size. — East Indies, Esper. — Ton- 
gatabu, E ip. Exp. 
26. Astr^a flexuosa {Dana). — Flexuoso-convex ; polyps 6 to 8 lines 
broad ; disks brownish-red, tentacles pale, with the tips yellow. Corallum 
firm and subcellular; calicles often contorted; cells 4 to 7 lines broad, deep, 
not coronate within ; ridges li to 2 lines thick, undulate, rounded, obsoletely 
truncate; lamellae even, crowded, rather stout, denticulate: in a transverse 
section, stars multiradiate, with the cellules decompound; septa often exceed- 
ing 1^ lines, solid, with few cellules. 
Plate 11, fig. 6, polyps partly expanded, natural size ; 6 a, tentacle, enlarged ; 
66, another in outline; 6 c, view of opening of mouth, enlarged; Qd, profile of 
cell, ridges and lamellae; 6c, vertical section of corallum, natural size. — Fee- 
jee Islands. — Exp. Exp. 
27. AstrjEa fusco-viridis {Quoy ^ Gaymard). — Convex; polyps 5 to 7 
lines broad, disks bright green, sometimes partly brown. Corallum firm and 
subcellular ; calicles usually oblong ; cells 4 to 6 lines broad, rather deep, ob- 
soletely or not at all coronate within ; ridges rounded, entire ; lamellae even, 
crowded, denticulate : in a transverse section, stars many-rayed, with the cel- 
lules decompound; septa nearly solid. 
Plate 11, fig. 7, animal unexpanded ; 7 a, another variety enlarged ; 7 6, ver- 
tical section, natural size; 7c, profile of cell, and lamellae enlarged. — Tonga- 
tabu, Quo?/ ^ Gaymard . — Feejee Islands, Exp. Exp. 
28. AstrjEA VIRENS {Dana). — Convex; whole surface bright green, polyps 
an inch broad. Corallum cellular, not very firm ; cells rather shallow, an- 
gular, and often oblong (4 to 6 lines), scarcely coronate within ; ridges rounded, 
entire ; lamellae even, crowded, denticulate, at apex spinoso-denticulate : in a 
transverse section, stars many-rayed, with the cellules much decompound ; 
septa i a line thick, cellules minute and scattered. 
Plate 11, fig. 8, polyps unexpanded; 8a, portion of corallum, natural size; 
8 6, profile of cell and lamellae, enlarged ; 8 c, vertical section of corallum, nat- 
ural size ; 8c^, transverse section of same. — ^Feejee Islands. — Exp. Exp. 
29. AsTRiEA echinata {Dana). — Convex; brownish-black, surface papil- 
lose ; polyps 6 to 8 lines broad, disks nearly black. Corallum cellular, surface 
strongly echinate; cells rather shallow, nearly circular or oblong; 5 lines 
broad, not distinctly coronate ; ridges rounded, not sulcate ; lamellae even, with 
3 or 4 small teeth within the cell, and 3 or 4 spines 1 to H lines long over the 
septum : in a transverse section, stars many-rayed, with the cellules decom- 
pound ; septa somewhat cellular, cellules oblong and often interruptedly uni- 
seriate. 
