Haddon and Shackleton — A Revision of the British Actinice. 651 



We are again indebted to our friend Canon Norman for specimens (identified by 

 Danielssen) of this species. Outwardly it differs from E. macintoshi in the rather 

 more clavate form mentioned above, and in the darker and more brownish colour. 

 Our specimens of either species are not sufficiently numerous to lay much stress 

 on the difference in the coenenchyme, which in many species varies much according 

 to the nature of the body to which the polyps are attached. Anatomically the 

 two species can be readily distinguished. The ectoderm of the body-wall in E. 

 norvegicus is very thick, and is crowded with nematocysts (PI. lix., fig. 5). In 

 E. macintoshi the ectoderm is very thin relatively to the diameter of the column, 

 and contains very few nematocysts (PI. lix., fig. 1). The incrustations in E. 

 norvegicus are various, consisting of spicules, grains of sand, and foraminifera. In 

 E. macintoshi they consist almost exclusively of foraminifera. The endoderm also 

 in E. norvegicus is much thicker than in E. macintoshi. The imperfect mesenteries 

 in E. norvegicus are remarkably well developed. In E. macintoshi they are feebly 

 developed, extending a very short way into the body-cavity.] 



Epizoanthus wrightii, n. sp. 

 (PL Lvm., figs. 30-33; PI. lix., fig. 3 ; PI. lx., fig. 2.) 



Form. — Column somewhat thick-set, body-wall incrusted but not particularly 

 rigid, 16 capitular ridges, mouth a narrow slit, with one oesophageal groove; 

 tentacles 32 in number, bicyclic, transversely corrugated when not fully extended. 

 Coenenchyme broad, flat, irregular. Polyps arise from the coenenchyme ; 

 craspeda ejected from the mouth when irritated. 



Colour. — Dirty pellucid- white or orange-pink; in both the disc is speckled with 

 opaque white ; tentacles with an opaque white tip ; craspeda, white or orange-pink, 

 according to the coloui' of the polyp. 



Dimensions. — Height, 13 mm.; diameter of column, 8'5 mm.; diameter of disc, 

 13 mm. ; length of tentacles, 13 mm. Average height of expanded spirit specimens, 

 4 mm. ; average diameter of column, 3 mm. In the contracted specimens the 

 height and diameter are about equal, or the latter may even be the greater. 



Habitat. — Dalkey Sound, Dublin Bay ; between tides ; spreading over incrus- 

 tations on the granite rocks but never actually attached to the granite itself. 



We are indebted to the brothers Dixon, for these specimens, and the above 

 description is mainly taken from an account recently published by them ("Notes 

 on the Marine Invertebrate Fauna of Dublin," Proc. Roy. Irish Acad., ser. iii., 

 vol. ii., p. 29, 1891). They very kindly placed all their specimens at our disposal. 

 We have the pleasure of dedicating this species to our friend Dr. E. Perceval 



4Z2 



