"A, diagram showing the sequence of mesenterial development in an Actinian. B, diagrammatic transverse section of Gonactinia prolifera." — The Encyclopedia Britannica, 1910

Actinian

"A, diagram showing the sequence of mesenterial development in an Actinian. B, diagrammatic transverse…

"Portion of epithelium from the tentacle of an Actinian, showing three supporting cells and one sense cell (sc); 2, a enidoblast with enclosed nematocyst from the same specimens; 3 and 3, two forms of gland cell from the stomodaeum; 5a and 5b, epithelio-muscular cells from the tentacle in different states of contraction; 5c, an epithelio-muscular cell from the endoderm, containing a symbiotic zooxanthelia; 6, a ganglion cell from the ectoderm of the peristome." — The Encyclopedia Britannica, 1910

Epithelium

"Portion of epithelium from the tentacle of an Actinian, showing three supporting cells and one sense…

"1, Portion of epithelium from the tentacle of an Actinian, showing three supporting cells and one sense cell; 2, a cnidoblast with enclosed nematocyst from the same specimen; 3 and 4, two forms of gland cell from the stomodaeum; 5a, 5b, epithelio-muscular cells from the tentacle in different states of contraction; 5c, an epithelio-muscular cell from the endoderm, containing a symbiotic zooxanthella ; 6, a ganglion cell fro mthe ectoderm of the peristome." —Encyclopedia Britannica, 1910

Tentacles

"1, Portion of epithelium from the tentacle of an Actinian, showing three supporting cells and one sense…