564 A. E. Yerrill — Anthozoa and Hydrozoa of the Bermudas. 



Two species of this genus are common and often found together, 

 on the rocks at low-tide, in tide pools, or even in exposed situations, 

 where they are often laid bare by the tide. Both are buff or pale 

 ochre-color and thickly encrusted with whitish sand. The more com- 

 mon is the species described as Corticifera lutea by Hertwig and as 

 C. glareola by McMurrich. As indicated above (p. 560), neither of 

 these names is correct. The zoOids are decidedly larger and the 

 tentacles (36-38) more numerous than in P. glareola. It forms 

 broad encrustations, often one to three feet in diameter, varying in 

 thickness up to one-half an inch or more (10 to 15'°™), with the 

 zooids 6 to 8™™ in diameter when expanded, or 6 to V™™ in contrac- 

 tion, and projecting, when fully contracted, only very slightly or 

 not at all above the coenenchyma, but in partial expansion forming 

 more or less prominent verrucoe, often nearly as high as broad. All 

 these various conditions can often be seen in the same cluster. PI. 

 Ixviii, fig. 7. 



This appears to be the earliest described species, Palythoa matn- 

 millosa (Ellis and Sol., 1780), of which their second species (ocellata) 

 was perhaps a synonym, differing only in the state of preservation. 



The other Bermuda species, remarkable for the large size of the 

 polyps and the extent to which they are free distally, appears to be 

 undescribed. (P. grandiflora V.) 



We did not find the real Palythoa glareola Les., at Bermuda. It 

 is distinguished mainly by the smaller size of the polyps (diam. 4°^'" 

 contracted) and the fewer mesenteries and tentacles (24, t. Les. ; 28-34 

 t. Duerd.). Perfect mesenteries about 16-17, often unsymmetrical 

 (t. Duerd.) ; 17 (t. Les., fig.). Disk violet (t. Les.). 



Its appearance and mode of growth are nearly the same as in 

 P. mammillosa, but it forms thinner crusts (about 5-8°^"'), though 

 perhaps of equal extent. It was well described and figured, with 

 anatomical details, by Leseur (op. cit.,pp. 178, 184, 185, pi. viii, figs. 

 6-9, 1817), and more fully, with histology, by Duerden (Jamaican 

 Actinaria, i, p. 365, pi. viii A, fig. 9, pi. xix, figs. 5-7, 1898) as P. 

 Caribcea D. and M. 



Palythoa grandiflora, sp. nov. 



Plate LXVIII. Figure 6. 



Zooids large, often free distally for about half their entire length, 

 and forming clusters (usually of 12 to 24) several inches across. 

 In contraction the zooids form large, rounded mammillae, often 

 higher than broad, strongly sulcated longitudinally, the grooves 

 (about 26) converging to the central depression of the summit; sur- 



