306 PROCEEDINGS OF THE ACADEMY OF [1888. 



tlie varieties (so-called) of the latter species figured by Pourtales are 

 really members of this sj)ecies. Its principal distinguishing char- 

 acters appear to be the thinner and more irregular septa, and the 

 terminal cleft that indents or separates the septa of opposing calyces 

 where they cross the common wall. It also presents a more bristling 

 iipjjearance than I. dijisacea. 



Isophyllia Guadeloupensis, Pourtales. 



One specimen. This appears to be a good species, although by 

 'Quelch it is referred lo Isoj^hyllia strigosa. 



In addition to these forms Quelch enumerates Isophyllia {Sym- 

 phyll'.a) marginata, I. cylindrica, and I. Knoxi, all of Duchassaiug 

 and Michelotti, as having been obtained at the Bermudas, but I 

 have failed to detect any specimens among our collections Avhich can 

 be confidently referred to these species. On the other hand, I find 

 ■one or two forms which I have not yet been able to identify with 

 any described forms. 



Siderastrsea galaxea, Ellis and Solander. 



Abundant on the shoals of Gallows Island, near the mouth of 

 Flatts Inlet, where the colonies come to within about two inches of 

 the surface; also on the borders of Harrington Sound. 



Porites clavaria, Lamk. 



Two specimens, dredged in Harrington Sound. 

 Torites astraeoides, Lamk. 



We found this species very abundantly along the outer reef, 

 -especially on the flats of the North Rock, where it is the dominant 

 form of coral. The species appears to have been overlooked by the 

 Challenger party, and indeed, the only reference that I have been 

 able to find indicating the occurrence of this common West Indian 

 form among the Bermudas is contained in Mr. Rathbun's list of 

 the species of Porites in the United States National Museum (Proc. 

 U. S. National Museum, 1887, p. 354). 



Mseandrina labyrinthica, Ellis and Solander. 



Three specimens, from the North Rock. 

 Mseandrina strigosa, Dana. 



This form is represented by large, sub-globose specimens, one of 

 which, obtained through purchase, and probably from Castle 

 Harbor, has an exceedingly attenuated base of attachment. The 



