A. E. Verrill — Comparisons' of Coral Faunae. 



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tion, and rounded, but many are narrowed and angular or subacute ; 

 all are terminated by two to four, more commonly three, strong, 

 sharp, erect teeth, giving the coral a rough and spinose appearance. 

 The inner edge is usually nearly perpendicular and thinner, and 

 is divided into a variable number, usually six to eight, of sharp 

 spiniform teeth, usually pointing strongly upward. These teeth of 

 the inner edge are generally decidedly smaller, shorter, and thinner 

 than the distal ones, but they are quite variable in size and form, 

 and some of them are sometimes about as large and wide as those 

 of the exsert portion, but not so thick. Sometimes they are all 

 subequal, but in other places they are very unequal. See figure 12. 



Figure 12.— Mussa annectens Ver. A series of outlines of the larger septa, 

 from the type specimen, enlarged ; a, b, two septa with true Mussa denti- 

 tion ; c, d, two septa with dentition of intermediate character ; e, f, two 

 septa of the Isophyllia type ; g, h, two septa from the outer side of marginal 

 calicles, to show the character of the costal spines. Drawn by A. H. Verrill. 



In the type specimens the septa are rather openly arranged, and 

 separated by interspaces exceeding their own thickness. But in one 

 example they are thicker and more crowded. They are unequal in 

 width and thickness, according to the three or four cycles that they 

 represent, those of the last cycle being almost rudimentary. There 

 are usually seven or eight larger ones to 10 mm in the type. The sides 

 of the septa are sharply granulated. The columella is well devel- 

 oped, trabecular, and covered with rough, irregularly divergent 

 spines. 



The under side is strongly lobulated near the margin and naked 

 for about 20 to 40 mra in the type, but much less in some others. The 

 costffi are rather coarse, irregular, in some places having somewhat 

 raised lamellae, with sharply serrate edges ; in other places low and 

 feebly toothed. 



Hamilton Harbor, Bermuda, on the reefs. 



