Verrill, Notes on Radiata. 395 



Corallum very branching, often in tlie form of a densely branched 

 shrub or bush, but frequently, especially when young, more or less fla- 

 belliform. The base is usually large and spreading, and quite fre- 

 quently several distinct trunks arise from the same base, forming a 

 thick clump. The trunk is very short and soon divides into several 

 large, divergent branches, which are nearly round, but sometimes a 

 little flattened, often more or less crooked, and give oiF from their 

 sides, at distances of about a fourth of an inch apart, numerous short, 

 irregular, crooked, and nearly quadrangular branchlets. Many of 

 these become longer and larger than the rest, and again subdivide in 

 the same way. The ultimate branchlets are usually about '08 of an 

 inch in diameter, and from half an inch to an inch long, ])ut occasion- 

 ally 2 inches. The terminal branchlets are mostly somewhat acute at 

 the ends. The cells form small rounded verrucoe, which are quite prom- 

 inent and closely arranged in two series on each side of the branches, 

 giving them a quadrangular appearance. On the larger branches the 

 verruca? are more scattei'ed and irregularly arranged. The openings 

 are mostly on the upper side of the verrucfe, and laterally compressed. 

 The branches and most of the branchlets have, along the naked me- 

 dian space, a well-marked longitudinal furrow, in which there is usu- 

 ally a slender longitudinal ridge. The axis is light wood-color at the 

 base, blackish in the main branches, slender and light wood-brown in 

 the branchlets. The coenenchyma is almost always either uniformly 

 greyish white or deep purplish red, but occasionally pink specimens 

 occur. One specimen has the lower branches and base white, the mid- 

 dle part of the trunk and the branches arising from it purplish red, 

 and the upper part of the trunk and terminal branches white, showing 

 conclusively that the white and red specimens are all one species. A 

 large specimen of the red variety is 8 inches high and 16 broad, with 

 the main liranches '15 in diameter; another is 13 inches high and 10 

 broad, with the main branches -22 in diameter. Most specimens do 

 not exceed 6 inches in height and about the same in breadth. 



Small dwarfed specimens sometimes occur that are 3 or 4 inches 

 high, with the main branches "08, and the branchlets -05 of an inch in 

 diameter, but agreeing in other respects -with the ordinary forms. 



The spicula in the white variety are all white ; in the red variety 

 light purple, the polyp-spicula bright yellow. The long double- 

 spindles are but little longer than the others, not very acute at the 

 ends, thickly covered wath distinctly separated, large, warty tubercles, 

 axis small. The stouter double-spindles are more blunt and more 

 closely covered with warts, which are still separate. Polyp-spindles 



