Haddon and Shackleton — A Revision of the British Adinice. 637 



Form. — Thickly incrusted forms, of which the well-grown polyps are twice as 

 higli as broad. Two well-marked varieties: — A. Incrusting form, coenenchyme 

 forming carcinsecia by replacement of a gasteropod shell ; the two primary polyps 

 at each end of tlie shell, usually forming a well-marked posterior marginal row of 

 polyps ; other polyps scattered on dorsal surface ; maximum number about 10—12, 

 varying much in height ; no polyps on the under surface of the carcineecium. 

 B. Free form, primarily consisting of two individuals base to base, each of which 

 may divide more or less regularly, or one only may divide. 



Colour. — Sandy. 



Dimensions. — Polyps, 3— 9 mm. in height; 1*5— 4*5 mm. in average diameter. 

 Colonies, greatest length, 22— 35 mm. ; greatest breadth, 13— 20 mm. 



Locality. — Shetlands ; W. and S. W. Ireland ; N. E. England ; Lerwick 

 (Barlee) ; 30 miles E. and N. of Brassey I., 70—80 faths. (Barlee) ; Haaf, Shetland, 

 1863 (A. M. N.); 5-8 miles E. of Balta, Shetland, 40-50 faths., July 20-23, 

 1867 (A. M. N.), " commensal with Pagurus Icevis " (PI. lviii., figs. 1-13) ; 

 also in St. Magnus Bay (A. M. N.); 40 miles S. W. of Cape Clear, Co. Cork, 

 80—90 faths., 1885, commensal with Eupagurus excavatus and Spiropagurus Icevis 

 (A. C. H.); Nymph Bank, Co. Cork, 50 faths., 1886 (A. C. H.) ; Clew Bay, 1890; 

 33-40 faths. off Aran, Co. Galway, 1891 (A. C. H.), (PI. lviii., figs. 14-22); 

 33-36, Donegal Bay, 1891 (A. C. H.); Scarborough (Bean, /. Johnston); 

 Northumberland, "deep water" (Alder) ; 48° 59' 42" N., 10° T 27" W., 90 faths., 

 1889 (G. C. Bourne), associated with E. meticulosus ; Plymouth Sound (specimens 

 in Mus. of Marine Biol. Assoc. Laboratory). 



The geographical distribution of this species is North Atlantic, extending from 

 the east coast of N. America to N. W. Europe. 



The synonymy of this species is much involved, but we think the foregoing 

 list is sufficiently complete. We agree with Norman in rejecting Johnston's 

 specific name, as he considered it to be a sponge ; and some years later (Hist. Brit. 

 Zooph., 2nd ed., 1847, p. 202) he quotes Couch's description of Z. couchii, and has 

 " the pleasure of naming this the only European Zoanthus after its discoverer." 

 It is therefore clear that he did not regard his own form as a Zoanthean. We are 

 thus obliged to adopt the specific name given to this species by Diiben and Koren. 

 Holdsworth, Gosse, and others have regarded this as a variety of E. couchii: we 

 think that it will be admitted from our anatomical studies that this is not the 

 case ; neither can it be associated with E. arenaceus, D. Ch. 



Owing to the kindness of Canon Norman we have been enabled to study some 

 authentic Norwegian specimens of this species, and find them to be identical with 

 the Shetland and Irish forms. 



Dr. Gray had no hesitation in referring some specimens from the coast of 

 Massachusetts, collected in forty-fathom water (Proc. Zool. Soc, 1867,. p. 237), to 



