1 80 A. E. Verritt — Comparisons of Coral Faunae. 



This interesting species is represented by three large specimens, 

 4 to 6 inches in diameter, with numerous calicles. They were 

 recently found in a lot of unassorted corals collected in Hamilton 

 Harbor by Mr. A. Hyatt Verrill, March, 1901, and hitherto over- 

 looked. 



It is clearly a true Mussa, as contrasted with Isophyllia, for the 

 distal, erect, exsert septal teeth are the stronger. The complete 

 union of the walls by exotheca would place it in Symphyllia, if that 

 group be recognized. 



It is more nearly related to 31. {Symphyllia) rigida Dana, of the 

 West Indies, than to any other known species. But it has much 

 larger calicles, and they are compound and much lobulated, and 

 rarely astreiform, as in the latter. The walls, also, are much less 

 solid. It also has a general resemblance to 31. (Isophyllia) multi- 

 flora, but the latter has thinner and more numerous septa, which are 

 toothed as in Isophyllia, and its calicles are smaller and more often 

 isolated. 



Mussa (Isophyllia) dipsacea (D.) Ver. See p. 118. 



Plate xviii, figs. 2, 5 ; pl. xix, figs. 2, 3 ; pl. xx, fig. 2. 



JRose Coral. Cactus Coral. 

 Occurs in the same places as the following ; common. 



Mussa (Isophyllia) fragilis (D.) Ver. See p. 121. 



Plate xvi, figs. 1, 2; pl. xvii, figs. 1-7; pl. xviii, figs. 1, 6; 



PL. xix, figs. 1, 4, 5. 



Hose Coral. Cactus Coral. 



Outer and inner reefs and rocks, and on shallow flats, very com- 

 mon ; Harrington Sd., common in 2-8 feet of water. 



Mussa (Isophyllia) multiflora Ver. See p. 125. 



Plate xx, fig. 1 ; pl. xxv, fig. 1. 



Outer reefs ; Serpuline atolls ; Hamilton Harbor, not common. 



The numerous other species of Isophyllia and Lithophyllia, 

 recorded by Quelch, are probably all varieties and young of 31. fra- 

 gilis and 31. dipsacea. 



