TRIBE III. MADREPORACEA. 473 



II. Calicidis validis; tubiformibus, dimidiatis aut nariformibus. 



45. MADREPORA FORMOSA. (Dana.) 



M. arborescens, gracilis, late valdeque ramosa, ramis viz bene teretibus, 

 3-6'" crassis, ramulis curvatis, attenuatis, proliferis. Corallum leve, 

 caliculo apicalifere $'" crasso et 1'" exserto ; lateralibus erectis, tenui- 

 tubiformibus, validis, 1-1 "' longis, vix confertis apice rotundatis ; 

 infra minoribus sed nuttis obsoktis, aperturd minutissima orbiculata, 

 stella conspicua. 



Arborescent, spreading, and much ramose, slender; branches scarcely 

 terete, 3 to 6 lines thick, branchlets curved, alternate, proliferous. 

 Corallum smooth, apical calicle nearly -J of a line broad, and 1 line 

 exsert; the lateral, small, erect, and stout tubiform, erect, 1-1 lines 

 long, scarcely crowded, rounded at summit; below much smaller, 

 but none obsolete; cell very minute and circular; star distinct. 



Plate 38, fig. 4, corallum, natural size; 4 a, extremity of branch; 

 plate 31, figs. 2 a, 2 b, views of calicle, enlarged. 



Feejee Islands, and Sooloo Sea, East Indies. Exp. Exp. 



This species is one of the neatest and most graceful of the arbores- 

 cent corals. It is distinguished by its rather crowded branchings, 

 smooth surface, and small tubiform calicles. It resembles, somewhat, 

 the brachiala, but is smaller and more ramose, and has a circular aper- 

 ture to the cells. It is very near the gracilis in general appearance 

 and size ; but has not the nariform calicles of that species. The tiny 

 trees are fifteen to eighteen inches high, and nearly as broad, and the 

 branches above are quite proliferous. 



Mad. muricata, Ellis and Solander, 171, tab. 57; Ellis's figure is a tolerably good 

 representation of this species ; his description is as follows : " Ramulosa, ramulis attenu- 

 atis, stellis prominentibus, cylindricis, oblique truncatis." The figure is referred by La- 

 marck to the M. abrotanoides : but neither the figure nor description represent it as having 

 immersed cells interspersed among the calicles. 



The figure of the Madrcjiont i>/(nitaginea of Quoy and Gaymard (Voy. de I'Ast., iv. 234, 

 pi. 19, fig. 3), presents nearly the characters of the extremity of a branch in this species. 



The lleteropom Hcinprichii of Ehrenberg, from the Red Sea, is near Iheformosa, but 

 has larger calicles and appears to grow differently. See op. cit. Gen. Ixix. sp. 6: "Semi- 

 pedalis, brevius ramoso-cespitosa, subfastigiata aut irregularis, violacea, ramis undique 



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