354 Verrillj Notes on Radiata. 



epitheca beneath. Cells subcircnlar, or deformed, open and deep, of 

 medium size (about '25 inch), smaller at the central part of the upper 

 surface, where they are crowded, with prominent, thin walls, which 

 are mostly separated about '08 inch, and united by a coarsely vesicu- 

 lar exotheca. Septa in three cycles (24 to 30), distant, very thin, 

 exsert, the summits angular or somewhat rounded, the costse or por- 

 tion outside the walls, very thin, elevated, deeply and unevenly 

 toothed, abruptly descending, so as to leave deep interstices between 

 the cells, except where they are crowded, when the costae of adjacent 

 cells unite, but the wall remains distinct. The septa, at summit and 

 within the cells, bear few distant slender teeth, descend perpendicu- 

 larly within, and have at the base a broad, thin, but not prominent 

 paliform lobe. Columella but little developed, of a loose, open tex- 

 ture. In a vertical section the walls are thin and continuous ; the 

 exotheca is composed of large rectangular, mostly simple vesicles, 

 which are horizontal and broader than high. The endotheca consists 

 of irregular, smaller, thinner-walled vesicles, which are often com- 

 pound and incline strongly downward toward the columella, which is 

 continuous, and coarsely spongiform in texture. 



Diameter of the only specimen obtained 5 inches ; cells '20 to '30. 



Abrolhos Reefs, Brazil, — C. F. Hartt, 



This is very distinct from all other American species. The very 

 open, deep, rounded cells ; few, thin, projecting septa ; and thin, dis- 

 tinct walls are very peculiar. 



Favia gravida Ven-m, sp. nov. 



Corallum solid and heavy, encrusting or hemispherical, with strong 

 epitheca beneath, evenly rounded above, with unequal, rounded^ oval, 

 and often deformed, deep cells, which are somewhat prominent above 

 the general surface, separated at unequal distances, leaving concave 

 interstices between them, which are strongly costate. Costfe thick- 

 ened, alternately larger and smaller, irregularly and roughly spinose- 

 dentate. Septa in four complete cycles (48) in the larger cells, un- 

 equal in width and height according to the cycles, those of the first 

 and second being nearly equal, the summits angular, projecting some- 

 what, and deeply toothed, the teeth and sides of the septa rudely 

 granulous. Paliform tooth well developed, rough. Coliunella very 

 little developed, open. Diameter of cells from "15 to '30 of an inch; 

 their prominence about '10. Diameter of the masses about three 

 inches, thickness half as much. 



Abrolhos Reefs, Brazil, — C. F. Hartt. 



