. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. ACTINIARIA 159. were developed, on the other side two mesen- teries of the 4th order were lacking. In the specimen from Ikamiut the number was 55 (6 + 6 + 12 + 24 + 7 — compare the table). The arrangement of the mesenteries thus seems commonly to be deca- merous, though it may happen to be hexame- rous. All mesenteries were perfect in the lar- ger specimens, in the smaller specimens the last C3'cle was not connected with the actinophary nx. The number of mesenteries seems sometimes to be a
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. ACTINIARIA 159. were developed, on the other side two mesen- teries of the 4th order were lacking. In the specimen from Ikamiut the number was 55 (6 + 6 + 12 + 24 + 7 — compare the table). The arrangement of the mesenteries thus seems commonly to be deca- merous, though it may happen to be hexame- rous. All mesenteries were perfect in the lar- ger specimens, in the smaller specimens the last C3'cle was not connected with the actinophary nx. The number of mesenteries seems sometimes to be a little smaller than that of the tentac- les, which indicates that also here the mesen- teries grow from the basis upwards, a rule, which perhaps holds good for all Cribrinids. The longitudinal muscles of the mesenteries recall those of Urticina, and the pennons appear as bands, a little but deeply folded. The parie- tobasilar muscles are well developed, though not as strong as in Urticina. The uppermost part is rather narrow, and the muscles end before reacliing the region of the sphincter. The basilar muscles are well developed and discoverable to the naked eye. Oral stomata are present, sometimes also marginal stomata, the latter, however, occur anything but regularly. All mesenteries are fertile, only on the directive mesen- teries they are often lacking (compare the table p. 160). The species is dioecious. Remarks. In this specimen I have never found any embryos in the coelenteric ca\dty. The most closely examined specimens were however male. A specimen was a double animal, each specimen had two pairs of directive mesenteries symmetrically arranged, perpendicularly to the dividing plane. The small fragments of the oral disc with tentacles, which Pax 1915 has determined as Actinostola abyssorum, certainly do not belong to this species but to Cribrinopsis similis. I have namely examined such tentacles taken in the Kola fiord (The Russian biological station) and labelled Zo
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
