TRIBE III. MADREPORACEA. 565 



II. Cellis omnino super ficialibus. 



20. PORITES INFORMIS. (Dana.) 



P. arrecto-glomerata, gibbosa-lobata et parce erosa ; polypis Jlavescentibiis 

 et brunneis, tentaculis obsoletis. Corallum cellis nullis, stellis non con- 

 spicuis, pord centrali minutissimd, inconspicua, sex granulis circum- 

 datd, exteriaribus duodedm sparsis. 



Stout erect glomerate, gibbons lobed, and sparingly erose ; polyps 

 pale-yellow, surrounded by brown, tentacles obsolete. Corallum 

 without cells, stars scarcely distinguishable, central pore very 

 minute, and surrounded by six granules; the outer 12 granules 

 scattered. 



Plate 55, fig. 6, corallum, natural size ; 6 a, polyps and surface of 

 zoophyte, enlarged ; 6 b, cells and surface of corallum, enlarged ; 6 c, 

 part of transverse section. 



Feejee Islands. Exp. Exp. 



This species differs from the erosa, in not growing in flat-top colum- 

 nar forms, and also in its cells. The specimen is an irregular mass, 

 three inches through, with a few nodular elevations. 



21. PORITES EROSA. (Dana.) 



P. arrecto-glomerata, columniformis, 2" animata ; apice plano-truncata, 

 erosa et profunde incisa; super -fide laterali parce monticulosd et 

 raro subcarinata. Corallum cellis nullis, stellis paulum conspicuis, ad 

 summitates inconspicuis, granulis sex et duodedm regularibus. 



Stout erect glomerate, columniform, alive for 2^ inches ; truncate at 

 summit, erose and deeply incised ; lateral surface sparingly monti- 

 culose, and rarely subcarinate. Corallum without cells, stars rather 

 distinct, except at apex, circles of 6 and 12 granules regular. 



Plate 55, fig. 8, corallum, natural size ; 8 a, cell, enlarged. 



Sooloo Sea. Exp. Exp. 



142 



