130 Proceedings of the Royal Irish Academy. 



the sphincter the alveoli are very small [PL XVIII, fig. 2), and are arranged 

 some singly, some in clumps of varying size, loosely or compactly. But at 

 the uppermost end of the sphincter the alveoli are larger and close together, 

 so that the clumps form networks. The sphincter does not exhibit vertical 

 or transverse layering. 



(iii -.—The radial musculature of the disc is entirely 



ectodermal, and is not much different from the tentacle-musculature. The 

 tentacles have thick but variable mesogloea, and high ectoderm, which, how- 

 ever, becomes poorer on the thickened outer side of the tentacle, especially 

 at the base. The entirely ectodermal longitudinal musculature forms a dense 

 fringe rouud the 2 the mesogloea. varying in width in different pain. 



The processes are fairly stout and _ itly branched, are moderately high 



in _ and rather moss-like in appearance. (PI. XVIII, 



i 7. The musculature almoE way on the ahoral side of the 



tentacle approached, and at the back of the basal swelling is 



hardly present. 



3 of the actinopbarynx 

 . granular gland-cells ; there are 

 also other gland-cells, rather like lea in appearance, 



which a i fair number of moderately long and narrow thick- 



walled oem ind there. The tentacle 



being unusually 

 big. There - ■ thick-walled blunt-ended cnidai _ i and more 



cylindrical than Dterial filament. Nuclei are most plentiful 



in the middle of the ectoderm. There are a large number of gland-cells of a 

 peculiar ich I hai lere. (PL XVI, figs. 5, 30.) The 



body of the 'ell i- -pink with eosin, and it contains black 



haematoxyli- - . mules which a □ few and very larg 



It has quite a different appearance from the usual granular gland-cell. There 

 are also pi ther type, which abc -:n with 



avidity. - in no black granules, and 



mo-' with hae ectoderm uf the body- 



wall ia much luwt-r than that of the tentacles, but is well and evenly 



nuclei, and thick-walled (shortel and 



proportional- -r than those in the ntiful, especially 



he margin, where they are crowded. Gland-cells of a type intermediate 

 between those of the tentacles and I are found, but are 



also eoeinophilouE i». The 



mesenterial filament-tinfoils have rather narrow stems to the three lobes. and 



»xl deal of mesogloea in each lobe. The ciliated lobes are often folded, 



