198 ZOOPHYTES. 



to the cell, of which there are about ten to a quarter of an inch in the 

 species examined ; moreover the stems break rather easily, while the 

 Mussae are very firm in texture. The broadly concave cell, as well as 

 the last character mentioned, separates them from the Euphylliae. 

 They approach the Caryophylliae, but increase by disk buds and sub- 

 division ; and besides, the coralla internally have the numerous trans- 

 verse dissepiments of the Astraeidae. They differ from the Manicinae 

 in not having the lamellae rounded above and regularly denticulate. 



The polyps of the only live species examined, never fully expanded; 

 they had a bright green disk, and appeared to be similar to the Mussae. 



The name of the genus is derived from xauXos, a stem, in allusion to 

 the cylindrical stems which constitute the clump. 



The species appear to be confined to the coral-reef seas. 



The Caulastrseae fall within Lamarck's genus Caryophyllia, Oken's 

 genus Mussa, and Schweigger's Lithodendrum. To this genus pro- 

 bably belong some of the Lithoderidra of Michelin. Schweigger's 

 name was introduced in place of Lamarck's Caryophyllia and Ocu- 

 lina, by him erroneously united, and has no claims to a place in the 

 Science ; and, besides, its signification (stone-tree} is inapplicable to 

 any of the included species, except the Dendrophylliae and Oculinae. 



1. CAULASTRJEA FURCATA. (Dana.) 



C. caulibus rectis,furcatis, vix undulatis, 3-5'" crassis; disco late virente. 

 Corallum undique obtuse striatum, leve; ramulis 1-2" elongatis, 4-6'" 

 animatis ; caliculis scepe tumidulis, ellipticis vel orbiculatis ; lamellis 

 numerosis, 1'" exsertis, suUntegris, subcequis, supra scepius angustatis. 



Stems straight, furcating, scarcely undulate, 3 to 5 lines thick; disk of 

 the polyps bright green. Corallum every where obtusely striate, 

 smooth; branchlets 1 to 2 inches long, alive for 4 to 6 lines; calicles 

 often a little tumid, elliptical or orbicular; lamellae numerous, 1 line 

 exsert, subentire, subequal, usually narrowing upward. 



Plate 9, fig. 4, animal unexpanded ; 4 a, one of the calicles ; 4 b, 

 transverse section of the same ; 4 c, an enlarged lamella. 



The Feejee Islands, in shallow water on the coral-reefs. Exp. Exp. 



