TRIBE I. ASTR^EACEA. 229 



Convex ; whole surface bright green, polyps ^ an inch broad. Co- 

 rallum cellular, not very firm ; cells rather shallow, angular, and 

 often oblong (4 to 6 lines), scarcely coronate within; ridges rounded, 

 entire ; lamellae even, crowded, denticulate, at apex spinoso-denti- 

 culate : in a transverse section, stars many-rayed, with the cellules 

 much decompound ; , septa a line thick, cellules minute and 

 scattered. 



Plate 11, fig. 8, polyps unexpanded ; 8 a, portion of corallum, na- 

 tural size ; 8 b, profile of cell and lamellae, enlarged ; 8 c, vertical 

 section of corallum, natural size ; 8 d, transverse section of same. 



Feejee Islands. Exp. Exp. 



This species has some resemblance to the favistetta, but the very 

 numerous rays to the stars, and their decompound cellules, distin- 

 guish it. The teeth at the summit of the ridge, though small, are 

 usually acute and spiniform, and often the two central ones are 

 smaller than the others, giving an appearance of a faint sulcus. 



29. ASTRJEA ECHINATA. (Dana.) 



A. convexa, brunneo-nigrescens et undique papillosa ; polypis6-8'" latis, 

 discis nigricantibus, vix depressis. Corattum cellulosum, valde echi- 

 natum ; cellis subprofundis, suborUculatis vel oblongis, 5'" latis, intus 

 non bene coronatis ; collibus rotundatis, non sulcatis ; lamellis regu- 

 laribus, infra S-A-denticulatis, supra septum echinatis, (3-4 dentibus, 

 1-1 "' elongatis) : transverse secto, stellis multiradiatis, cum cellulis 

 decompositis ; septis subcellulosis, cellulis oblongis scepe interrupte 

 uniseriatis. 



Convex ; brownish-black, surface papillose ; polyps 6 to 8 lines broad, 

 disks nearly black. Corallum cellular, surface strongly echinate ; 

 cells rather shallow, nearly circular or oblong ; 5 lines broad, not 

 distinctly coronate; ridges rounded, not sulcate; lamellse even, with 

 3 or 4 small teeth within the . cell, and 3 or 4 spines 1 to 1 J lines 

 long over the septum : in a transverse section, stars many-rayed, 

 with the cellules decompound ; septa somewhat cellular, cellules 

 oblong and often interruptedly uniseriate. 



58 



