Elementary text-book of zoology, general part and special part: protozoa to insecta . elementarytextbo00clau Year: 1892 24S CCEUIXXEllATA. Fig. l^T.âII,n!ttemma tergcsir, S. Nectocalyx; P, polyp; Pn, pneumatnphore; aydroplij-llium ; J^7câ , { provisional appendages is formed which allows us to regard the develop- ment of the Siphono' phora asa metamoi-phosis (lig. 188 and 189). The croAvn of hydro- phyllia, which is com- pleted by the addition of fresh hydrophyllia after the appearance of a tentacle with provisional groups of nematocysts, persists only in Atliory- hia, where a swimming col
Elementary text-book of zoology, general part and special part: protozoa to insecta . elementarytextbo00clau Year: 1892 24S CCEUIXXEllATA. Fig. l^T.âII,n!ttemma tergcsir, S. Nectocalyx; P, polyp; Pn, pneumatnphore; aydroplij-llium ; J^7câ , { provisional appendages is formed which allows us to regard the develop- ment of the Siphono' phora asa metamoi-phosis (lig. 188 and 189). The croAvn of hydro- phyllia, which is com- pleted by the addition of fresh hydrophyllia after the appearance of a tentacle with provisional groups of nematocysts, persists only in Atliory- hia, where a swimming column with nectocalyces is never formed. In A(jalmoj)sis and Thysophora the primary hydrophyllia of the larva fall off as the stem be- comes larger, and are replaced by nectocalyces. (1) Sub-order: Fhyso- plioridce. Stem short, extended in the form of a sac (fig. 190), or elongated spirally (fig. 191), with a pneumato- phore, usually nectocaly- ces, which are arranged in two or more rows on a swimming column below the pneumatophore. Hydrophyllia and dacty- lozooids are usually , and alternate with the polyps and gonoph(;res in regular order. The body of the larva usually develops voups of nematocjEts.
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