290 BULLETIN OF THE MUSEUM. 



and they have their fullest development in recent seas. There are none 

 living now, however, on the Pacific coast of America, hut Symphylliae, 

 Myeetophylliae, Manicinse, and other genera of the Lithophylliacees me'an- 

 droides of Milne-Edwards and Haime are very abundant and characteristic 

 of the West Indian Fauna. 



Convexastraea ? peruviana n. sp. (Plate, figs. 4 and 5.) 



Mostly in small spheroidal masses, from 1 to 8 cm. in diameter. Calicles 

 crowded, small (2 mm. in diameter), deep. Septa thick, with apparently 

 smooth edges, in six regular systems and three cycles, the primary septa 

 alone reaching the centre, but leaving a small space between the ends. 

 Septa of adjacent calicles sometimes coalescing. No distinct Avail or furrow 

 perceptible between the calicles. No pali or columella visible, although a 

 small space in the centre looks as if it had been occupied by the latter. 



This fossil, which at first sight reminds one of a Porites, on account of 

 the size of the calicles and general aspect, comes nearest the genus Convex- 

 astraea, and particularly Convexastra\i Waltoni Edw. & PI. Still I am not 

 quite satisfied with this identification. The species of that genus described 

 thus far belong to the Jurassic and Triassic formations. 



Explanation of the Plate. 



Fig. 1. Isophyllia duplicata n. sp. Nat. size. 



" 2. Magnified portion of the same. 



" 3. Single calicle nearly circumscribed, magnified. 



" 4. Convexastra?a ? peruviana n. sp. Nat. size. 



" 5. Calicles of the same magnified. 



