656 Haddon and Shackleton — A Revision of the British Actinice. 



region by well developed mesogloeal plaitings. Lower down the plaitings 

 disappear, the muscles forming an almost simple layer. Close to the disc a bundle 

 of transverse fibres are seen on the opposite side of each mesentery to that which 

 bears the longitudinal fibres. These seem to be the prolongations of the 

 endodermal muscles of the disc and tentacles. The reflection of the ectoderm of 

 the oesophagus, and its connexion with the filaments, can be well seen in this 

 species (PL lx., fig. 6). The mesogloea and the endoderm appear to be 

 involved to some extent in the reflection also. The endoderm of the mesenteries 

 forms, for the most part, a very thin layer, but it is much thickened in the region 

 of the filaments (PI. lx., fig. 7), the mesenteries in this region resembling those of 

 Z. macgillivrayi (PI. lxiv., fig. 8), but the thickening is not so marked as in that 

 species, nor do we find here either zooxanthellse or nematocysts. 



Gonads. — In one of our specimens male gonads are present. They are 

 surrounded by a thickened layer of endoderm (PI. lx., fig. 7). 



Parazoanthus anguicomus (Norm.). 

 (PI. LViiL, figs. 34-36; PI. lix., figs. 11, 12.) 



Zoanthus sulcatus ? : 



Bowerbank, 1867, Prioc. Zool. Soc, p. 351. 

 Zoanthus anguicoma : 



Norman, 1868, " Shetland Eeport," Rep. Brit. Assoc, p. 319. 

 Polyihoa [Tceniothoa) anguicoma : 



Andres, 1884, Le Attiuie, p. 317. 

 Palythoa, sp. : 



Eidley, 1886, Proc. Roy. Irish Acad. (2), iv., Sci., p. 617. 

 Palythoa anguicoma : 



Hertwig, 1888, Suppl. "Challenger" Rep., Actiniaria, p. 46, pi. i., fig. 7. Is probably 

 not P. anguicoma, but an allied species, P. hertwigi, n. n. 



Form. — Body rigid, rough; in some specimens the column has an almost warty 

 appearance; capitular region swollen when contracted; radial ridges about 18 in 

 number, prominent, rough. Tentacles in two cyles, of about 17 in each, very long 

 and extensile, more tlian equal to diameter of disc when fully exjDanded; gradually 

 attenuating to very slender points. Coenenchyme incrusted, thin, either band-like, 

 creeping on sponges and other objects, or foi'ming broader expansions. The 

 coenenchyme is never well developed, and sometimes the pol^^ps are isolated or in 

 small groups. The smaller specimens, when contracted, have a button-like 

 appearance. 



Colour. — Pinkish-white (Norman) ; sand colour in preserved specimens. 



