Haddon and Shackleton — A Revision of the British Actinice. 641 



Sphincter muscle. — The mesogloeal sphincter muscle is short, and consists of 

 well-defined cavities. 



Disc and Tentacles. — The disc and tentacles present the usual structure. The 

 muscular layers appear to be feebly developed. 



(Esophagus. — The shape of the oesophagus in cross-section varies in our speci- 

 mens. Sometimes it is almost circular (PL lx., fig. 1), the groove forming a 

 very slight depression ; in other specimens the groove is fairly-well marked. 

 The ectoderm is almost smooth, being but very slightly folded. 



Mesenteries. — The arrangement of the mesenteries is macrocnemic. The 

 imperfect mesenteries are very slightly developed, extending into the coelenteron 

 but little beyond the endoderm. The ectoderm of the oesophagus is reflected, and 

 forming a series of folds along each mesentery, is continued downwards in the 

 usual manner to form the mesenterial filaments. The mesogloea of the mesentei'ies 

 is slightly developed. The muscle-fibres form simple layers, there being no 

 mesogloeal plaitings. The endoderm of the mesenteries i.-s thin, resembling that 

 of the body-wall. 



Gonads. — There were no gonads in the specimens examined by us. 



Var. barleei. — The specimens we have cut of the free variety agree very closely 

 in their anatomy with the above account ; but the sphincter muscle appears to be 

 longer and more powerful. 



Epizoanthus paguriphilus. 

 (PI. LviiL, figs. 23-25 ; PI. lix., fig. 6 ; PI. lx., fig. 5.) 



Epizoanthus pagurijiMhis : 



Verrill, 1882, Am. Journ. Sci. (3), xxin., pp. 137, 316; 1883, Bull. Mus. Comp. Zool., 

 Cambridge, Mass., xi. (1883-85), p. 61, pi. vm., fig. 6 ; 1884, Am. Fish. Com. Rep. for 1882, 

 p. 658; 1885, Am. Pish. Com. Eep. for 1883, p. 535, pi. vm., fig. 28. Bourne, 1890, Journ. 

 Marine Biol. Assoc, i., p. 318. 



Zoanthus (Corticantlius) pagiiriphiliis : 



Andres, 1884, Le Attinie, p. 326. 



Form. — Colonies always forming carcinsecia ; slightly incrusted; mesogloea 

 very thick ; one polyp on ventral surface, the remainder forming a radiating 

 single row, the " posterior polyp " of which is the smallest. 



Colour. — Brownish in spirit specimens, but bluish-gray in colour where the 

 thin incrustation is rubbed away. 



Dimensions. — Average diameter of coenenchyme, 55 mm. ; average height of 

 polyps, 20-25 mm. ; average width of polyps, 12—16 mm. ; average thickness of 

 polyps, 8—10 mm. 



lEANS. EOT. DUB. SOC, N.S. VOL. IV., PART XII, 4 T 



