TRIBE I. ASTR^EACEA. 1Q7 



with the gyri 1 inch broad ; septa stout, solid, scarcely cellular ; 

 lamellae unequal. 



Plate 8, fig. 11, worn fragment of the corallum; 4 a, vertical sec- 

 tion of the same. 



Wake's Island, Pacific Ocean. Exp. Exp. 



The long and often straight trenches, an inch wide, distinguish 

 this species from the preceding, when in worn specimens, the only 

 condition in which it was met with ; four smaller lamellae appear to 

 intervene between the larger, and these last are a fourth to a third of 

 an inch apart. The septum in the worn specimen is about an eighth of 

 an inch wide, and obtusely rounded. The polyp-centres are convoluto- 

 porous and a little prominent. In a vertical section, the transverse 

 dissepiments on the lateral surface of a lamella are seen to be very 

 numerous and delicate, forming neat lines, running obliquely across 

 them. 



17. MUSSA NOBILIS. (Dana.} 



M. glomerata, subhemispherica, aut planiuscula, discis sinuosis, viren- 

 tibus ; ore albido ; tentaculis brevissimis. Corallum gyris 1-1 J" 

 latis ; lamellis incequalibus, spinoso-dentatis, minoribus alternis ; cotti- 

 bus integris. 



Glomerate, subhemispherical or nearly plane; disks long sinuous, 

 green ; mouth white ; tentacles very short. Corallum, with the 

 gyri 1-1 inches broad ; lamellae unequal, spinoso-dentate, small and 

 large alternating ; ridges entire. 



Plate 8, fig. 10, worn fragment of the corallum. 



Port Carteret, New Ireland, Quoy and Gaymard. Wake's Island, 

 Pacific, Exp. Exp. 



The above description is by Quoy and Gaymard. The size of the 

 trenches is taken from their figure, which they state to be two-thirds 

 the natural size. They represent the lamellae as very coarsely dentate. 



Worn specimens were obtained at Wake's Island, which have 



