TRIBE III. MADREPORACEA. 
87 
exsert; the lateral very closely crowded, short labellate, equal and erect, 
nearly four-fifths of a line broad ; stars rather distinct, two of the lamellae 
most prominent. 
Plate 35, fig-. 5, corallum, natural size. — Feejee Islands. — Ex'p. Exp. 
40. Madrepora exigua [Dana). — Arborescent, spreading ramose, slender, 
branches terete, scarcely 3 lines thick, curved and acuminate. Corallum hav- 
ing the lateral calicles very short, round-nariform, hardly f of a line broad, a 
little crowded, cell round, six-rayed, sometimes two of the lamellae a little 
prominent. 
Plate 38, fig. 2, corallum, natural size ; 2 cr, extremity of a branch, ditto *, 
2 &, profile of calicles. — Feejee Islands. — Exp. Exp. 
41. Madrepora cribripora [Dana). — Arborescent or cespitoso-arbores- 
cent, spreading ramose, branches neatly terete, 4 to 5 lines thick, branchlets 
long (some 3 inches), attenuate, and subacute. Corallum scabrous, very po- 
rous ; apical calicle stout (1 to 1^ lines), quite long, striate ; the lateral very 
short, round-nariform, fragile, a little crowded, cell open ; star obsolescent, 
one inner lamella prominent. 
Plate 31, fig. 1, zoophyte expanded, natural size; 1«, polyp enlarged; 1&, 
extremity of branch of corallum ; 1 c, surface of corallum, enlarged ; trans- 
verse section of branch, enlarged. — Feejee Islands, about shallow parts of 
reefs. — Exp. Exp. 
42. Madrepora gravida [Dana). — Arborescent, very large, spreading 
and distant ramose, branches very stout (1 to 2 inches), terete, summits gradu- 
ally becoming conical, and sides covered with oblong conical ramiculi, i an 
inch in length. Corallum having the apical calicles broad (1 to l^- lines), a 
little tumid, but not prominent; the lateral calicles of the ramiculi quite small 
and very closely crowded, short labellate and fragile, the others throughout 
obsolescent. 
43. Madrepora virgata [Dana). — Slender arborescent, spreading and 
remotely ramose, branches scarcely | inch in diameter, very long, neatly 
terete and even, subarcuate, polyps not proliferous. Corallum scarcely po- 
rous, minutely granulous, lateral calicles small, rather crowded, very short 
and thin tubular, margin acute ; cell circular, star with six short rays, two a 
little the most prominent. 
Plate 39, fig. 1, corallum, natural size, — The Feejee Islands. — Exp. Exp. 
44. Madrepora horrida [Dana). — Arborescent, very large, divaricately 
and remotely branched, branches below 1 to 2 inches thick, nearly terete, 
curved, gradually attenuate, throughout very proliferous, with divaricate rami- 
culi 1 to 2^ inches long. Corallum bristled with calicles and scabrous ; apical 
calicle tubiform, not incrassate; the lateral, thin-tubiform, divaricate, and 
