200 ZOOPHYTES. 



Hemispherical clumps, stems straight, crowded ( of an inch distant), 

 subcylindrical, undulate. Corallum thick, throughout rugately 

 striate and denticulate, calicles an inch broad, sometimes dilated 

 and compressed; lamellae numerous, triangular, subacute at apex 

 and a little exsert, subdenticulate; cell conical, bottom narrow, arid 

 of very open texture. 



Plate 9, figure 6, profile section of calicle. 



The long undulate stems, nearly cylindrical, are striate and finely 

 denticulate over the exterior for several inches in length, and so 

 closely and erectly branched that the intervals in the clump between 

 the calicles are but one-eighth of an inch broad. The line of demar- 

 cation between the live and dead part of the calicle is scarcely distinct. 

 The bottom of the conical cell is very open cellular, being formed of 

 only a few entangled fibres. The clump examined is five inches 

 high, and was probably from the West Indies. 



This species approaches the Madrepora fastigiata of Esper (i. 95, 

 tab. 8); but the cells are more open, the lamellae less broad, and the 

 branchlets, judging from Esper's figure, much more crowded. 



GENUS VII. ASTR^EA. LAMARCK. 



Astrceidce aggregates; discis simplicibus, raro distomatis aut tristomatis; 

 tentaculis brevibus. Corolla convexa, scepius bene hemispherica, in- 

 terdum arrecto-gibbosa, aut glomerato-incrustantia ; cettis ezcavatis, 

 multi-radiatis, suborbiculatis, interdum angulatis, aut sublobatis ; 

 lamellis usque ad medium septi longiusve productis. 



Aggregate Astraeidae; disks simple, rarely two or three mouthed; ten- 

 tacles short. Coralla convex, usually neat hemispherical, rarely 

 erect-gibbous, or glomerato-incrusting ; cells excavate, many-rayed, 

 nearly circular, sometimes angular or somewhat lobed ; lamellae ex- 

 tending over the surface between the cells, and usually interrupted 

 at the middle of the septum. 



The Astraeae, though sometimes irregularly nodular or gibbous, usu- 



