. Elementary text-book of zoology. Zoology. II VDROZOA. 233 Th Septa but slightly developed. Mudn/ini-i/ cervicornis Lain., I)rnd i-o/ih ri/ Hint Edw,, Mediterranean, Axt ruiilc-x calycularis Pall. CLASS II.— * [HYDEOZOA.] Polyps without ajsophayeal tithe, with ximple gastrovascular cavil;/. The generative elements are devduj><'<l. in medusoid forms n-Jtich may be either free-sn'i in in iiiij, r jwrnianentltj attached to hi/droid forms. This class includes the small polyps and polyp stocks, and the Medusce which form the sexual generation. The Polypomedusce have
. Elementary text-book of zoology. Zoology. II VDROZOA. 233 Th Septa but slightly developed. Mudn/ini-i/ cervicornis Lain., I)rnd i-o/ih ri/ Hint Edw,, Mediterranean, Axt ruiilc-x calycularis Pall. CLASS II.— * [HYDEOZOA.] Polyps without ajsophayeal tithe, with ximple gastrovascular cavil;/. The generative elements are devduj><'<l. in medusoid forms n-Jtich may be either free-sn'i in in iiiij, r jwrnianentltj attached to hi/droid forms. This class includes the small polyps and polyp stocks, and the Medusce which form the sexual generation. The Polypomedusce have always a simpler structure than the Anthozoa to which they are also usually infe- rior in size. They lack oesophagus, septa, and gastrovas- cular pouches. Only the polyps of the a- sexual generation of the Scyphomedusa? [Acraspeda], known as Scyphistoma, pos- sess a remnant of the gastric folds as four gastric ridges from which filaments are developed. The polyp stocks develop in rare cases (Mille- poridce) a compact calcareous framework comparable to the polyparium. When skeletal formations are present they con- sist as a rule of more or less horny secre-. FIG. Iso it. Branch of an Olielia-stnek lO, fieluflnnxa). O, Mouth of a nutritive polyp with extended tentacles. J/, Medusa buds on the body of a proliferous polyp ( style) ; Th, bell-shaped cup (theca) of a nutritive polyp. tions of the ectoderm, which as delicate tubes surround the stem and its ramifications, and sometimes form small cup-like structures surrounding the polyp, and known as * Eseholtz, "System cler Acalephen,'' Berlin, 1829. Th. Huxley, "Memoir on the Anatomy and Affinities of the Medusae," Phil. Trans., London, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Claus, Carl, 1835-1899; Sedgwick, Adam, 1854-19
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
