TRIBE III. MADREPORACEA. 475 



Arborescent, spreading ramose, branches terete, 6 to 9 lines thick, 

 upper branchlets often more than 3 inches long, arcuate, gradually 

 attenuate. Corallum somewhat scabrous, apical calicle quite broad 

 (U lines), exsert, cell | a line broad; the lateral equal, rather 

 crowded, tubiform, and striate, truncated at apex a little obliquely, 

 erect, not compressed, 1 to 1^ lines long, but on the inferior side of 

 the branches very short ; star very distinct. 



Plate 40, fig. 2, extremity of branch, natural size. 



Sooloo Sea, East Indies. Exp. Exp. 



This species closely resembles the secunda, differing principally 

 from it in its tubular calicles. It has the wide-spreading branches of 

 the cervicornis, and has probably been referred to that species, though 

 smaller and different in its calicles. 



Madrepora muricata, Esper, Pflanz. Fortsetz. i. tab. 49. Esper states that his spe- 

 cimen was brought from Madagascar. The figure is referred to the cervicornis by 

 Lamarck. 



48. MADREPORA ROBUSTA. (Dana.} 



M. arbwescens, late ramosa, ramis |-1" crassis, teretibus, ramulis ex- 

 tremis vix minoribus, scepe 2-3" eiongatis, apice subito acuminatis et 

 conicis. Corallum caliculo apicali crasso (1J'" lato], vix exserto; late- 

 ralibus undique confertissimis et divaricatis, paulum incequalibus, 

 sapius tuUformibus et !"' longis, vix compressis, bene striatis, aliis 

 minoribus apice valde obliquis ; stella sex-radiata conspicud, duabus 

 lamettis prominulioribus. 



Arborescent, spreading ramose, branches f to 1 inch thick, terete, 

 branchlets but little smaller, 2 to 3 inches long, abruptly taper- 

 ing at apex and conical. Corallum having the apical calicles 

 stout (1.3 lines broad), but slightly exsert; the lateral every where 

 much crowded, standing erect on the surface, a little unequal, 

 mostly tubiform, and lj lines long, scarcely compressed, neatly 

 striate, the smaller very oblique at summit ; star 6-rayed, distinct, 

 2 of the rays most prominent. 



Plate 39, fig. 3, part of corallum, natural size ; 3 a, extremity of 

 branch; plate 31, figs. 3 a, b, c, views of calicles, enlarged. 



