TRIBE I. ASTR^EACEA. 263 



lamellae very finely denticulate, and very much crowded ; fossae re- 

 pand, at bottom convolute-porous. 



West Indies. 



The porous bottom of the cell, as well as the very much more 

 crowded lamellae, separates this species from the gracilis and tennis. 

 There are thirty-six to forty lamellae to half an inch, and fifteen to 

 twenty of these are slightly appendiculate at base. It grows to a 

 breadth of two or three inches. 



Madrepora filograna, Esper, Pflanz. i. 139, of Lamarck, which he describes as fol- 



tab. 22, fig. 1; the figure is characteristic, lows : " Globosa, subgibbosa, anfractibus 



although coarse, and represents well, in superficialibus, angustissimis, tortuosis ; 



an enlarged view, the porous bottom of lamellis parvis, remotis, collibus filiformi- 



the cell. The lamellae are not sufficiently bus. East Indies." (ii. 389, No. 9. 



crowded. This is not the M. filograna Deslongchamps, Encyc., 509.) 



b. Septis crassis, apice truncatis. 



12. MEANDRINA CEREBRIFORMIS. (Lamarck.} 



M. hemispherica; discis linearibus pralongis, tortuosis ; gyris 5'" latis. 

 Corallum cettulosum, robustum ; collibus 3'" latis, perpendicularibus, 

 subrotundatis et obtuse, sukatis ; septis apice J" crassis; lamellis 

 numerosis, denticulatis, tenuibus : transverse secto, septis subcellulosis. 



Hemispherical ; linear disks very long and tortuous ; gyri 5 lines 

 broad. Corallum cellular, firm ; ridges 3 lines broad, perpendicu- 

 lar,- somewhat rounded and obtusely sulcate above ; septa of an 

 inch thick at apex; lamellae numerous, denticulate, thin : in a trans- 

 verse section, septa subcellular. 



Plate 14, figure 2, section of trenches and ridges, showing also pro- 

 file of lamellae. 



Bermudas and West Indies. 



This species like the labyrinthica grows to a large size. It is the 

 common brain coral. The ridges are broad, and usually somewhat 

 sulcate at top, and perpendicular within the cell, with sometimes a 

 constriction in the sides half way to the bottom, proceeding from an 



