. Elementary text-book of zoology. Zoology. SCYPHOMEDUS^E MAHSUPIALIDA. 259 modified. As in Lucemaridcie, the vascular spaces arc wide pouches divided from each other by four narrow septa (figs. 1!»S} 199). The nervous system is allied to that of the Hydromedusce by the presence of a sharply denned nerve-ring. This nerve-ring is placed on the .sub-umbrella side of the bell, and, since at the bases of the four sense organs it lies further from the margin than it does at the corners of the bell, it has a sharply marked, zig-zag course. The nerve fibrillfe given off from it mostly supply the musc
. Elementary text-book of zoology. Zoology. SCYPHOMEDUS^E MAHSUPIALIDA. 259 modified. As in Lucemaridcie, the vascular spaces arc wide pouches divided from each other by four narrow septa (figs. 1!»S} 199). The nervous system is allied to that of the Hydromedusce by the presence of a sharply denned nerve-ring. This nerve-ring is placed on the .sub-umbrella side of the bell, and, since at the bases of the four sense organs it lies further from the margin than it does at the corners of the bell, it has a sharply marked, zig-zag course. The nerve fibrillfe given off from it mostly supply the muscular system of the sub-umbrella, and there give rise to numerous reticula of nbrilla? connected writh large ganglion cells. Large bundles of fibrilhe com- p;i ruble to nerves have only been found in the four radii of the mar- ginal bodies. The latter attain a high degree of development, since the knob-like swelling in which they terminate possesses, in addition to the lithocyst, a complicated visual apparatus consisting of two large unpaired median eyes and four small paired lateral eyes. The generative organs have a. very peculiar form. They are separated from the gastric filaments and as thin, rather broad plates attached in pairs to the four partition walls, length of the Unfortunately known of the. mar- FIG. 199.—The apicalhalf of a Charybdea divided transversely, seen from the sub-umbrella side. The four oral arms are visible. Oc, Ovaries on the four septa, S; Ost, ostia of the gas- tric pouches; Gf, gastric filaments. reach the whole vascular pouches, nothing is as yet development. Fam. Charybdeidae. Cli<injlnl<'<t xMjt'niTix Per. Les. (Murxiipiulix Plum-i Les.) Mediterranean. (3) Sub-order: Discophora (Acra- speda), Ephyra-medusce. Disc-shaped Accuepha, the margin of ivhose disc is divided into eight lobes. They have at least eight sub-marginal sense organs contained in niches, and with the same number of ocular lobes. As a rule there are four great cavities
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
