"Tangential section of a larva of Astroides calicularis which has fixed itself on a piece of cork. ec, Ectoderm; en, endoderm; mg, mesogloea; m, m, mesenteries; s, septum; b, basal plate formed of ellipsoids of carbonate of lime secreted by the basal ectoderm; ep, epitheca." — The Encyclopedia Britannica, 1910

Astroides Calicularis

"Tangential section of a larva of Astroides calicularis which has fixed itself on a piece of cork. ec,…

"Gelatinous substance of the disc of Aurelia, showing-a, fibrous trabeculae, and b, wandering endoderm cells, with amaebold movements." — Encyclopedia Britannica, 1893

Aurelia

"Gelatinous substance of the disc of Aurelia, showing-a, fibrous trabeculae, and b, wandering endoderm…

"Portion of the body-wall of Hydra, showing ectoderm cells above, separated by "structureless lamelia" from three flagellate endoderm cells below. The latter are vacnolated, and contain each a nucleus and several dark granules. In the middle ectoderm cell are seen a nucleus and three nematocysts, with trigger hairs projecting beyond the cuticle. A large nematocyst with everted thread, is seen in the right-hand ectodermal cell." — Encyclopedia Britannica, 1893

Body-wall

"Portion of the body-wall of Hydra, showing ectoderm cells above, separated by "structureless lamelia"…

"Diagram of a Diblastula. a, orifice of invagination (blastopore); b, archenteric cavity; c, endoderm; d, ectoderm." — Encyclopedia Britannica, 1893

Diblastula

"Diagram of a Diblastula. a, orifice of invagination (blastopore); b, archenteric cavity; c, endoderm;…

"Formation of the Diblastula of Eucope (one of the Calyptoblastic Hydromedusae) by delamination. A, B, C, three successive stages. ep, ectoderm; hy, endoderm; al, enteric cavity." — Encyclopedia Britannica, 1893

Diblastula

"Formation of the Diblastula of Eucope (one of the Calyptoblastic Hydromedusae) by delamination. A,…

"Vacnolated endoderm cells of eartilaginous consistence from the axis of the tentacle of a Medusa (Cunina)." — Encyclopedia Britannica, 1893

Endoderm Cell

"Vacnolated endoderm cells of eartilaginous consistence from the axis of the tentacle of a Medusa (Cunina)."…

"Diagram of a typical Hydrozoan polyp. EC., Ectoderm; EN., endoderm; C., the cavity of the gut (coelenteron); G., a reproducive bud; T., a tentacle; H., hypostome or oral cone; M., mouth." -Thomson, 1916

Hydrazoan Polyp

"Diagram of a typical Hydrozoan polyp. EC., Ectoderm; EN., endoderm; C., the cavity of the gut (coelenteron);…

"Diagram showing possible modifications of persons of a gymnoblastic Hydromedusa. a, hydrocaulus (stem); b, hydrohiza (root); c, enteric cavity; d, endoderm; e, ectoderm; f, perisarc (horny case); g, hydranth (hydriform person) expanded; g', hydranth (hydriform person) contracted; h, hypostome, bearing mouth at its extremity; k, sacciform gonophor (sporosac) springing from the hydrocaulus; k', sporosac springing from m, a modified hydriform person (blastostyle): the genitalia are seen surrounding the spadix or manubrium; l, medusiform person or medusa; m, blastostyle." — Encyclopedia Britannica, 1893

Hydromedusa

"Diagram showing possible modifications of persons of a gymnoblastic Hydromedusa. a, hydrocaulus (stem);…

"Diagram showing possible modifications of the persons of a Calyptoblastic Hydromedusa. a, hydrocaulus (stem); b, hydrohiza (root); c, enteric cavity; d, endoderm; e, ectoderm; f, perisarc (horny case); g, hydranth (hydriform person) expanded; h, hypostome, bearing mouth at its extremity; i, the horny cup or hydrotheca of the hydriform persons; l, medusiform person springing from n, a modified hydriform person (blastostyle); n, the norny case or gonandium enclosing the blastostyle and its buds. This and the hydrotheca i give origin to the name Calyptoblastea." — Encyclopedia Britannica, 1893

Hydromedusa

"Diagram showing possible modifications of the persons of a Calyptoblastic Hydromedusa. a, hydrocaulus…

"Portions of sections through the disc of medusae. The upper one of Lizzia, the lower of Aurelia. el, endoderm lamelia, or vascular lamelia; m, muscular processes of the ectoderm cells in cross section; d, ectoderm; en, endoderm lining the enteric cavity; e, wandering endoderm cells of the gelatinous substances." — Encyclopedia Britannica, 1893

Medusae

"Portions of sections through the disc of medusae. The upper one of Lizzia, the lower of Aurelia. el,…

"Simple tentaculocyst of one of the Trachomedusae (Rhopalonema velatum). The process carrying the otolith or concretion hk, formed by endoderm cells, is enclosed by an upgrowth forming the "vesicle," which is not yet quite closed in at the top." — Encyclopedia Britannica, 1893

Trachomedusae

"Simple tentaculocyst of one of the Trachomedusae (Rhopalonema velatum). The process carrying the otolith…