TRIBE III. MADREPORACEA. 431 



FAMILY I. MADREPORID^E. 



Madreporacea polyporum basi medio non coralligena; itaque, corallorum 

 cdtts valdt profundis et penitus non transverse septatis. 



Polyps not coralligehous at middle of base; cells of the corallura 

 therefore, very deep, and not crossed by septa within. 



The Madreporidse include the most common branching corals. As 

 many of them bud from a parent or apical polyp, their forms are often 

 arborescent, and among them are found some of the largest of coral 

 trees. Besides these there are shrubby clumps, reticulate fronds, 

 vases, and large foliated species, as elsewhere explained. 



This family comprises but two genera, which are closely related, 

 although separated widely by previous authors. The genus Madre- 

 pora, includes species which bud from a parent-polyp, with which 

 each branch terminates. They have regular calicles, and the branches, 

 although not always erect, are neat and cylindrical, except when this 

 character is lost by their coalescence. But two or three species 

 are known in which the apical polyp cannot be distinguished, and 

 these form a connecting link between this genus and the following. 



The genus Manopora comprises incrusting, glomerate, and foliaceous 

 or branched Madrepores, in which there is no proper apical polyp, 

 and the calicles are either obsolete or very irregular. The deep cell, 

 traceable far within the corallum, without any cross divisions, sepa- 

 rates these zoophytes from those of the following families. These 

 cells are never over half a line in diameter. 



The Madreporidse, with one or two exceptions, have been found 

 only in the coral-reef seas. 



GENUS I. MA DRE FOR A. LINN. 



Madreporidce patrio-ramosce ; arbwescentes, cespitosce, interdum reticu- 

 latce aut coalescenter foliacece. Corolla ramis teretibus; caliculis re- 

 gularibus. 



