. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. 26 MEDUSA. eggs, the nuclei of which may, for some time, be seen in the protoplasm of the developing egg, but are gradually absorbed and disappear. The four perradial, longitudinal muscular bands in the manubrium are still narrower than in Eii- physa tentaculata; the number of muscle cells seen in a cross-section only amounts to 4 or 6 in each l^and, alike in botli sexes. â In other respects the section, textfig. 21, might as well illustrate the manubrium of E. tentaculata. â As in th
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. 26 MEDUSA. eggs, the nuclei of which may, for some time, be seen in the protoplasm of the developing egg, but are gradually absorbed and disappear. The four perradial, longitudinal muscular bands in the manubrium are still narrower than in Eii- physa tentaculata; the number of muscle cells seen in a cross-section only amounts to 4 or 6 in each l^and, alike in botli sexes. â In other respects the section, textfig. 21, might as well illustrate the manubrium of E. tentaculata. â As in the latter species, also here the mouth is surrounded by a slightlj- elevated ring con- taining ncmatocysts. Accordingly, it is due to a mistake, when Hartlaub (1907), in the diagnoses of the subgenera Euphysa and Steenstrupia (in contradistinction to AinaUlKra) points out the lack of oral nematocysts ("ohne orale Nesselarmatur"). In Euphysa aurata more than one tentacle is never developed; the three other bulbs are rudimentary and much smaller than the tentaculiferous bulb; the one opposite the latter is smaller still tlian the two lateral Ijulbs. The bulbs have Fig. 22. Euphysa aurata. i .-, ^ ⢠7- , i , , 7 , / .- > , longitudinal section of ru- nearly the same shape as ni Euphysa tentaculata (see texthg. 22), only, as a rule, dimentary marginal bulb; somewhat broader in the radial directitm (Plate I, figs. 10â11). observe the purelj' ectoder- mal spur. ,, . â 1 / r\, . TTT^ , â r , 1 Material (see Chart IV : umbrella; r. c. radial canal; ^ ' sp. spur; sub. suburabrella; Disco Bay, West-Greenland, Ivat. 69°27' N., 54°io' W. August i6th V. velum. â The gelatinous substance is somewhat 19^9- Plankton-uet, horizontal haul about loo m below tlie surface. Temperature shrunk. - Specimen ^f ^^^ ^^.^^^j. ^o <. po^sild. â I Specimen, the Skaw, Denmark. â X 50- Geographical distribution and seasonal occurrence. The Hydroid:
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
