ClipArt ETC
"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…