POLYPS AND CORALS. 39 



edge of the cells where the principal ones are thin and 

 somewhat salient, forming at intervals short crests. The 

 branches and corallites are surrounded by transverse ridges 

 or wrinkles at irregular intervals. These are unequal in 

 size and not very prominent, giving an undulated appearance 

 to the surface. In the axils between adjacent corallites the 

 edges of the brandies are strongly compressed, thin and 

 often acute. 



The cells are irregular and contorted, mostly simple, 

 with a narrow and deep central space. Septa in five cycles 

 very unequal, thin, not crowded, the primary ones nearly 

 meeting at the centre, the inner edges nearly perpendicular, 

 summits obtusely rounded, scarcely exsert. Walls very thin 

 and compact. 



Height six inches ; diameter of cells .5 to .75. 



Bonin Islands. Dr. Wm. Stimpson. 



This is nearest to E. striata E. and H. It has larg- 

 er and less open cells, and less regular costal striations. It 

 also branches in a different manner. 



GrALAXEA FASCICULARIS Oken ( ?) 



A Galaxea closely allied to or identical with this species, 

 occurs in the collection, represented by only one specimen. 

 Although differing in some points from the present species, 

 under which Edwards and Haime unite several species, con- 

 sidered distinct by others, I do not deem it justifiable to 

 separate it without more specimens, for the species of this 

 genus are quite variable, and the differences are not well 

 marked, in the dry corals, at least. 



The corallites are united to within half an inch or less 

 of their summits by a rather loose peritheca, having numer- 

 ous dense layers at intervals of about one fourth of an inch. 

 The mass is somewhat convex above, and about two inches 

 thick. The Corallites are mostly cylindrical above the pe- 

 ritheca, except the young ones which are turbinate, many 

 are compressed or somewhat irregular where crowded. The 

 wall is nearly smooth, with costse prominent and crest-like 

 close to the summit, but indicated below by mere striae, sep- 

 ta very prominent in three cycles, those of the two first 



