the Actiniarian Family AliciiJaj. 7 



to regard the two as distinct. It is not likely that the 

 two distin<;ui.shcd zoojjhytologists would have neglected the 

 elongated capitulum had it been preserjt in their torm. 



Dunodeopsis antilUejisis, sp. ii. (PI. I. figs. 1-4.) 



Form (PI. I. figs. 1, 2). — Base adherent, rarely free, irre- 

 gular in outline, generally oval-shaped, thin-walled, and 

 transparent, so that the mesenteries and internal organs can 

 be seen through, margin crenate, surface thrown into ridges 

 and grooves corresponding with the attachment of the perfect 

 and imperfect mesenteries. 



Proximal part of column covered with pedunculate irregu- 

 larly arranged outgrowths or vesicles of various sizes com- 

 municating with the coelenteron ; most are large, compound, 

 and shortly clavate, having a narrow peduncle ; others are 

 spheroidal or papillate ; the larger may bear digitiform out- 

 growths, others are merely tuberculate, and others again have 

 only thickened ridges. These may almost disappear when the 

 vesicles are fully inflated, the surface being then nearly 

 smooth, the ridges and tubercles showing as slightly thickened 

 more opaque bands. The tubercles and bands on microscopic 

 examination are seen to be batteries of large nematocysts. 

 Column-wall expanded and short proximally, not readily seen 

 owing to the presence of the abundant vesicles ; upper part 

 or capitulum only visible when the animal is extended, long, 

 cylindrical, and smooth, much less in diameter than the 

 vesicular area, but enlarging towards the disk ; walls ex- 

 tremely thin throughout, pellucid, the darker coloured 

 oesophagus clearly seen through. 



Tentacles completely and readily retractile, elongate, 

 smooth, entacmieous, subulate, thin-walled, transparent, 

 variable in number, arranged in several cycles according to 

 the formula 6, 6, 12, 24. Examples with 12, 18, 24, 30, 36, 

 48, and higher numbers are met with ; outer arise directly 

 from the margin of tiie disk ; capable of great extension ; over- 

 hang the column-wall ; covered with minute urticating spots. 

 In full extension they are very delicate structures, readily 

 detaching when handled. Disk larger in diameter than the 

 capitulum, very thin-walled, the attacimient of the mesenteries 

 showing through ; peristome generally elevated into a cone 

 with the oral aperture at the apex ; mouth oval-shaped, six 

 well-marked ridges and grooves on each side; no gonidial 

 groove. The disk, tentacles, and naked portion of the column- 

 wall are usually completely infolded, so that no external 

 indication of them is left. 



