. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. l82 ACTINIARIA Colour? Dimensions in contracted state: length and breadth about 2,2 cm. Occurrence: 20' E. off Cape Jakan 12 fms. Sand and clay with stones (Vega-Hxp.) i sp. Together with E. marsupialis. Exterior aspect. The pedal disc is well developed and the column smooth, without spots. The fossa is deep, the tentacles from conical to cylindrical, smooth and rather thick, in number probably as many as the mesenteries. Only about 20 tentacles were, however, perspicuous, but as I have ob
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. l82 ACTINIARIA Colour? Dimensions in contracted state: length and breadth about 2,2 cm. Occurrence: 20' E. off Cape Jakan 12 fms. Sand and clay with stones (Vega-Hxp.) i sp. Together with E. marsupialis. Exterior aspect. The pedal disc is well developed and the column smooth, without spots. The fossa is deep, the tentacles from conical to cylindrical, smooth and rather thick, in number probably as many as the mesenteries. Only about 20 tentacles were, however, perspicuous, but as I have observed some involved tentacles in the weakest compartments, I think that the number of tentacles and mesenteries is the same. Concerning the appearance of the actinopharynx I cannot give any perfect informations, as it was very contracted and badly preserved, and partly in a mess with the reproductive organs. It is, however, distinctly longitudinally sulcated. Anatomical description: The ectoderm of the column is high and contains numerous mucus- cells and nematocysts (size compare the diag- nosis). The mesogloea is thick, and the en- dodermal circular muscles much weaker than those of the former species. The sphincter is of a decidedly palmate type (textfig. 182), on transverse sections round and well-developed. The ectoderm of the tentacles is high, the nematocysts and the spirocysts (compare the diagnosis) numerous. Their longitudinal nmsc- les (textfig. 181) are strong, and recall those of Cribrina sfetsbergensis, but are ectodermal; there is but rarely a mesogloeal mesh at the base of the muscle folds. The radial muscles of the oral disc are weaker, especially at the insertions of the mesenteries. Here the muscles. Fig. i8i Fig. 182 Tcxtfigs. 181, 182. Epiactis incerta. Transverse sections of part of a tentacle (fig, iSi) and of the sphincter (fig. 182). seem to show a tendency to become mesogloeal, whereas they are ectodermal between the mesenteries. The nematocysts of th
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
