Verrill, Xotes on Radiata. 501 



upper part of the polyps elongated, cylindrical, much exscrt above the 

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

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

 simple, but generally compound by budding, rarely by fissiparity. 



Family, Madreporid^e Dana. 



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



MadreporidoR {pars) and Foritidce {pars) Edw. and H., Corall., iii, p. 89 and 207, 

 18G0. 



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

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

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

 usually of two sorts in each species : in 3Iontipoi'a diflering on the 

 opposite sides of folicaceous species ; in Madrejwra the terminal one 

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

 twelve radiating septa, often rudimentary, but usually continuous. 

 Polyps small, tubular, exsert, with twelve tentacles. 



This family, as limited by Prof. Dana, ap})ears to be a very natural 

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

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

 former as a subfixmily, Madreporince, to their large family Madrcpori- 

 dce, which includes also Eiipsammidce and TurM?iaridm, both of which 

 ouglit to rank as families. Montipora they unite with Psainmocora 

 into a subfamily, Montiporinm, which is referred to Poritidce. 



But the Poritidce are destitute of the abundant coenenchyma and 

 deep cells, characteristic of 3Iadrepora and Montipora. Tlie resem- 

 blance between certain species of these tAvo genei-a, both in appear- 

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

 Madrepora there is usually a terminal, or leading polj^p at tiie end of 

 each branch, Avhich 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, 3fadrepora, 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 Amer- 

 ica, and the genus 3Iontipora.^ which is abundant in the Indo-Pacific 

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

 one species. 



