TRIBE III. MADREPORACEA. 509 



29. MANOPORA TORTUOSA. (Dana.} 



M. ramosa, ramis scepe 4" longis, \" crassis, curvatis vel tortuosis, sub- 

 teretibus, compressiusculis. Corallum omnino kve, cellis immersis, 

 \'" latis. 



Ramose, branches- often 4 inches long, \ of an inch thick, curved or 

 tortuous, subterete, somewhat compressed. Corallum quite smooth, 

 cells immersed, J of a line broad. 



Plate 48, fig. 2, corallum, natural size. 



Singapore, East Indies. Exp. Exp. 



This species resembles the digitata, in its Mittepore habit and gene- 

 ral size ; but the branches are much longer and less crowded, and the 

 cells are larger. 



FAMILY II. FAVOSITID^. 



Madreporacea polyporum basi seriatim coralligena, itaque cellis fundo 

 solidis, et penitus, transverse septatis, aut raro solidescentibus ; calicu- 

 lis nullis. 



Polyps intermittedly coralligenous at base, cells, therefore, solid at 

 bottom, and within the corallum crossed by septa, or quite closed 

 by the secretions ; calicles none. 



The polyps of the Favositidse, as far as examined, scarcely differ 

 externally from the Madreporae, except that the tentacles are shorter. 

 Their coral secretions are at once distinguished by the transverse 

 septa, or cross-partitions of the cells, a structure exhibited when the 

 interior is laid open by a cross-fracture. In a few slender species, 

 these secretions seem to lose their intermittent character, or, if it is 



128 



