AND EXPLANATION OF TERftlS. 
3 
The WARTS {verrucce)^ in some speeies, are hollow, and 
furnished with a muscular arrangement by which a vacuum 
is formed, and the edges adhere firmly to foreign bodies ; 
these may be called suckers {acetahula). Other species 
have the skin and the muscular beds beneath it pierced 
with minute orifices, for the emission of armed threads ; 
these may be called loop-holes {cinclides). 
3. The Disk {Facies). 
This is the flattened upper extremity of the column, as 
the base is the flattened lower extremity. Its outline is 
circular ; and this is recognised without difficulty when, as 
is usually the case, the edge is plane {plana) ; but some- 
times the edge is wavy {undulata), as in hellis ; or even 
deeply frilled {sinuosa)^ as in dianthus. In Actinia 
proper, the disk bears, just within its margin, a row of 
spherules {splicerulce marginales) ; and, in every species, it 
carries the tentacles, and is pierced at the centre by the 
mouth. Converging lines {radii) cover the surface of the 
disk, starting from each tentacle-foot and meeting around 
the mouth. One radius on each side of the disk, leading 
to each mouth-angle {gonidium)^ is often more marked 
than the rest ; these may be termed GONIDIAL radii {radii 
gonidiales). 
4. The Tentacles {Tentacula). 
These are hollow cones springing from the siu'face of the 
disk, and arranged in one or more series of circles towards 
its margin. When there are more circles than one, that 
circle which is nearest the centre may be called the first 
ROW {series prima) ; that which stands next to it towards 
the margin the SECOND {series secunda) ; and so on till we 
reach the outermost {series extima). Witli respect to 
each individual tentacle, its FRONT {untied) is that aspect 
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