Stephenson — Certain Actiniaria collected off Ireland. 139 



iv General histology. — The ectoderm of the tentacles has the usual battery 

 of large spirocysts; but it varies in thickness a good deal, and of course when 

 a tentacle is much distended the ectoderm is very thin, and then there is ool 

 room for the spirocysts, and they have to lie sideways in it. There are long, 

 narrow, blunt-ended, thick-walled cnidae, with a light "keel" or a dark 

 central streak (probably the spiral thread). These are plentiful in the basal 

 swellings, also in the tips of the tentacles. There are numerous large, irregular 

 or rounded finely granular gland-cells, and smaller ones not visibly granular. 

 The body-wall ectoderm, where it remains, is less well developed than that 

 of the tentacles ; it contains thick-walled cnidae like those of the tentacles. 



The mesenterial filament-trefoils have well-marked ciliated lobes, usually 

 larger than the short glandular ones, and they stain very deeply. The glan- 

 dular parts contain many coarsely granular gland-cells of various forms and 

 sizes, many of them elongate ; also long, large thick-walled nematocysts in 

 the large glandular-filament, but much smaller needle-like ones in the 

 trefoils. 



17. C. pulchra n. sp. 

 PL XIY, fig. 4 ; IT. XVI, figs. 13-15; PL XVIII, tigs. 13-16.) 



Three specimens in an unlabelled jar. 



Measurements.— (i) Largest specimen. Diameter of oral disc and tentacles, 

 3 - 8 cm. ; of column at its widest, 4 - 4 cm. ; of lower part of column, 2 cm. ; 

 length of pedal disc, 3'5 cm. ; breadth of pedal disc, '9 cm. ; height of column, 

 3 "4 cm. 



(ii) Smallest specimen. Diameter of oral disc and tentacles, 1-6 cm. 



External characters. — In all cases the pedal disc is elongated in the line of 

 the axis of the actinopharynx and its grooves. It is modified for attachment 

 to cylindrical objects, which in this case are spines of an Echinoderm. It 

 has a well-marked edge, and is thin and membranous, seemingly with no 

 cuticle, although in one case much of the outer layer of the spine has stuck 

 to the anemone. Column approximately the same shape in all, much exceeded 

 by the pedal disc in one axis, exceeding it in the other. The pedal disc is 

 rolled round the spine, its opposite edges meeting, but not fusing. Lower 

 part of column cylindrical and pillar-like, upper part expanding suddenly and 

 considerably exceeding it (PL XIV, fig. 4), and then curving inward again a 

 little to the margin of the oral disc. The wall is tough and hard, rather thin 

 below, but quite thick in the upper part. Lower part almost smooth or 

 finely papillate, upper part with numerous prominent pointed tubercles, of 

 various sizes and irregular arrangement. These attain their best development 

 a little below the margin, the uppermost rim being almost smooth. They are 



[T 2] 



