88 
TRIBE III. MADREPORACEA. 
sometimes reversed ; very unequal, some of an inch long, others interspersed 
obsolescent, others proliferous ; star six-rayed. i 
Plate 39, fig. 2, corallum, natural size; 2a, extremity of branch, natural 
size. — Feejee Islands.— Exp^ ' 
45. Madrepora FORMOSA (Dana).— Arborescent, spreading, and much ra- 
mose, slender ; branches scarcely terete, 3 to 6 lines thick, branchlets curved, 
alternate, proliferous. Corallum smooth, apical calicle nearly four-fifths of a 
line broad, and 1 line exsert; the lateral, small, erect, and stout tubiforrn, 
1-1^ lines long, scarcely crowded, rounded at summit; below much smaller, 
but none obsolete; cell very minute and circular; star distinct. 
Plate 38, fig. 4, corallum, natural size ; 4a, extremity of branch; plate 31, 
figs. 2a, 2 6, views of calicle, enlarged. — Feejee Islands, and Sooloo Sea,* . 
East Indies. — Exp. Exp. | 
46. Madrepora bkachiata {Dana). — Arborescent, spreading, and re- 1 « 
motely ramose ; branches long, straight, nearly terete, 6 to 8 lines thick, upper 
branchlets often 3 inches long, apex sparingly proliferous. Corallum rather 
smooth, lateral calicles crowded, subequal, erect, compressed tubiforrn, stout, II 
obliquely truncated at apex ; exterior very minutely striated, aperture oblong; 
star distinct, two of the lamellae much the most prominent. 
Plate 38, fig. 3, part of corallum, natural size ; 3 a, extremity of branch ; 
36, profile of calicle, natural size. — The Sooloo Sea, East Indies. — Exp. Exp. 
47. Madrepora arbuscula {Dana). — Arborescent, spreading ramose, 
branches terete, 6 to 9 lines thick, upper branchlets often more than 3 inches 
long, arcuate, gradually attenuate. Corallum somewhat scabrous, apical cali- 
cle quite broad (1^ lines), exsert, cell i a line broad; the lateral equal, rather 
crowded, tubiforrn, and striate, truncated at apex a little obliquely, erect, not 
compressed, 1 to H lines long, but on the inferior side of the branches very 
short ; star very distinct. 
Plate 40, fig. 2, extremity of branch, natural size. — Sooloo Sea, East Indies. 
— Exp. Exp. 
48. Madrepora robusta {Dana). Arborescent, spreading ramose, 
branches f to 1 inch thick, terete, branchlets but little smaller, 2 to 3 inches 
long, abruptly tapering at apex and conical. Corallum having the apical cali- 
cles stout (li lines broad), but slightly exsert; the lateral every where much 
crowded, standing erect on the surface, a little unequal, mostly tubiforrn, and ' 
1^ lines long, scarcely compressed, neatly striate, the smaller very oblique at 
summit; star 6-rayed, distinct, 2 of the rays most prominent. 
Plate 39, fig. 3, part of corallum, natural size; 3a, extremity of branch ; 
plate 31, figs. 3 a, 6, c, views of calicles, enlarged. — Feejee Islands. — Exp. Exp. 
