TRIBE III. MADREPORACEA. 495 



Erect-subcespitose, inciso-lobate, compressed, angular and alate, lobes 

 often cultrate. Corallum fragile, surface partly spinuloso-asperate, 

 cells rarely bordered by papillae, very distinctly 6-rayed; crests 

 without cells. 



Plate 46, fig. 1, part of corallum, natural size. 



Red Sea. Ehrenberg. Singapore. Exp. Exp. 



The clumps are often a foot high and the same in breadth, and 

 consist of erect thin lamellate branches, having a sharp edge above ; 

 they are often vertically winged. The cells are generally nearly 

 naked ; but occasionally there are a few minute spinuliform papillae 

 about them, which sometimes run into thin longitudinal ridges. The 

 cells are one-third to one-half a line broad. Under the microscope the 

 surface is very neatly laciniate-porous, or consists of mossy points 

 about the pores. 



7. MANOPORA SPUMOSA. (Lamarck.} Dana. 



M. arrecto-subcespitosa, gibboso-subramosa, lobis brevibus, crassis, scepe 

 tubercutato-gibbosis, raro angulosis, apice interdum subclavato. Co- 

 rallum fragile, confertim spinuloso-asperum, apice papillis crassioribus 

 et obtusis ; cellis immersis, margine non tumidis, stetta 6-12-radiatd. 



Subcespitose, erect, gibboso-subramose, lobes short, stout, often tuber- 

 culato-gibbous, rarely angular, sometimes subclavate at summit. 

 Corallum fragile, crowdedly spinuloso-asperate, papillse at apex 

 much stouter than elsewhere and obtuse ; cells immersed, margin 

 not tumid, star 6 to 12-rayed. 



Plate 44, fig. 4, corallum, natural size. 



Singapore, East Indies. Exp. Exp. Red Sea. Ehrenberg. 



A coarse stout species, growing erect ; the stems are very thick and 

 irregular, often coalescing laterally, find have tuberculate ascending 

 lobes rather than branchlets. The summits are usually a little angu- 

 lar, with stout papilla? or irregular incipient ridges, instead of spines. 

 The spines of the lateral surface are crowded and slender, and about 

 a line long. The cells have usually more than six rays. Under the 



