Verrill, Xotes on Radiata. 501 



upper part of the polyps elonfjatod, cylindrical, much exscrt ahove tlic 

 cells when expanded, but capable of contracting into them ; growth 

 chieilv vertical. Coral porous, chiefly mural and septal ; sometimes 

 simple, but generally comi)Ound by budding, rarely by fissiparity. 



Family, Madkepokid.e Dana. 



Zoophytes, U. S. Exploring Expedition, p. 431, 184G. 



Madreporidce {pars) and Foritidce {pars) Edw. and II., CoralL, iii, p. 89 and 207, 

 18G0. 



Corals always compound, increasing by budding, consisting of small, 

 elongated, tubular corallites, which have very deep, open cells, and 

 are united by an abundant, porous coenenchyma. The corallites are 

 usually of two sorts in each sjiecies : in 3Iontipora difiering on the 

 opposite sides of folicaceous species ; in JSIadrepora the terminal one 

 on each branch dilFering from the lateral. Within the cells are six or 

 twelve radiating septa, often rudimentary, but usually continuous. 

 Polyps small, tubular, exsert, with tw^elve tentacles. 



This family, as limited by Prof. Dana, appears to be a very natural 

 one, and includes but two genera : Madrcpora and Montipora. These 

 have been widely separated by Edwards and Haime, who refer the 

 former as a subfamily, Madreporince^ to their large family Madrepori- 

 d<-e, which includes also Eiipsammidm and Turhinaridce, both of which 

 ought to rank as families. Montipora they unite with Psammocora 

 into a subfamily, Jlotitiporince, which is referred to Poritidw. 



But the Poritidm are destitute of the abundant coenenchyma and 

 deep cells, characteristic of Madrepora and Montipora. The resem- 

 blance between certain species of these two genera, both in appear- 

 ance and structure, is very close, the chief difference being that in 

 Madrepora there is usually a terminal, or leading polyp at the end of 

 eacli branch, which is not the case in Montipora. In each genus there 

 are branching, foliaceous, encrusting, and massive species. The resem- 

 blance in the living polyps, as observed by Dana, is equally close. 



The great genus, Madrepora., so abundant in species and individu- 

 als in the West Indies and on the Atlantic coast of Central America, 

 and especially in the central Pacific, East Indies, Indian Ocean, and 

 Red Sea, appears to be entirely wanting on the west coast of Amei*- 

 ica, and the genus Montipora., which is abundant in the Indo-Pacific 

 region, but entirely wanting in the Atlantic, is represented only by 

 one species. 



