A. JE. Verrill — Bermudian and West Indian Reef Corals. 153 



Siderastraea radians (Pallas) Ver. 



Madrepora radians Pallas, Elench. Zooph., p. 322, 1766. 



Madrepora galaxea Ellis and Sol., Zooph., p. 168, pi. xlvii, fig. 7, 1786. 



Asirea galaxea Lara., Syst., p. 371, 1801 ; Hist., ii, p. 267, 1816. Lesueur, 



op. cit., p. 285, pi. xvi, fig. 3, 1820. Lanix., op. cit., p. 60, pi. xlvii, fig. 7, 



1821. 

 Astrea radians Oken, Lehr. Nat., p. 65, 1815. 

 A-frea (Siderastrea) galaxea Blainv., Diet. Sci. Nat., lx, p. 335, 1830; Man. 



Actin., p. 370, 1834. 

 Astrma radians Edw. and Haime, Hist. Corall., ii, p. 506, 1857. Gregory, op. 



cit., p. 277, 1895. 

 Siderina galaxea (pars) Dana, Zooph., p. 218, pi. x, figs. 12, 126, 12c. (Type 



examined.) 

 Siderastrcea galaxea Edw. and Haime, Ann. Sci. Nat., xii, p. 139, 1850. Pour- 

 tales, Reef Corals, p. 81, 1871 ; Florida Reefs, pi. xi. figs. 14-21, young, 



pi. xv, figs. 1-12, 1880. Quelch, op. cit., p. 113, 1886. 

 Siderastrata radians Verrill, Bull. Mns. Comp. Zool., i, p. 55, 1864; Coral 



Reefs and Islands, p. 380; ed. 3, p. 421. Vaughan, op. cit., p. 61, 1901. 



Plate XXX. Figure 1. 



This coral usually forms rounded spheroidal or hemispherical 

 masses, which may become 12 to 15 inches (400 to 500 min ) in diame- 

 ter ; but it is often encrusting, especially when young, and it often 

 grows in broad irregular masses; not infrequently it is almost globu- 

 lar and lies loose on the bottom, with calicles developed on all sides. 

 Such loose masses are most commonly 2 to 5 inches (50-1 25 mm ) in 

 diameter. They were doubtless all attached when very young, but 

 perhaps only to small bits of shell, etc. 



The calicles are deep in the center and small, their diameter when 

 full grown is mostly 2.5 to 3.5 mm , the average size being about 3 mm , 

 rarely 4 mm . They are angular with rounded corners, and usually 

 appear as if separated by thick Avails, owing to the low rounded 

 summits of the walls, which are, however, actually rather thin, with 

 one or two rows of small synapticula? showing on each side. 



The septa are decidedly unequal in width and thickness, those of 

 the first two cycles standing out very plainly from the others. They 

 form three complete cycles, with part of the fourth cycle developed, 

 so that the number is usually 36 to 40, in the larger calicles, (rarely 

 48). But the size of the calicles and the number of septa vary con- 

 siderably on a single specimen, according to the amount of crowding, 

 or the rapidity of growth. 



The septa are closely arranged, with very narrow loculi. The 

 larger ones are wide, broadly rounded, somewhat exsert, with all the 

 edge pretty evenly serrulate, though the distal serrations are apt to 

 be rather larger. The six primaries are distinctly larger than the 



