Archive image from page 289 of The Danish Ingolf-expedition (1899-1953). The Danish Ingolf-expedition danishingolfex5bpt5a8daniuoft Year: 1899-1953 138 HYDROIDA II Hydrallmaniafalcata has its chief occurrence in the littoral region of the boreal seas, and may exceptionally penetrate deeper down into the abyssal, where it has, however, once or twice been ob- served at 2000 metres depth. The species can move right up into arctic waters, and has even been met with in the Kara Sea; otherwise, its occurrence coincides with the presence of warmer currents in the high arctic areas. It may also pene

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Archive image from page 289 of The Danish Ingolf-expedition (1899-1953). The Danish Ingolf-expedition danishingolfex5bpt5a8daniuoft Year: 1899-1953 138 HYDROIDA II Hydrallmaniafalcata has its chief occurrence in the littoral region of the boreal seas, and may exceptionally penetrate deeper down into the abyssal, where it has, however, once or twice been ob- served at 2000 metres depth. The species can move right up into arctic waters, and has even been met with in the Kara Sea; otherwise, its occurrence coincides with the presence of warmer currents in the high arctic areas. It may also pene
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Image ID: W27KMF
Archive image from page 289 of The Danish Ingolf-expedition (1899-1953). The Danish Ingolf-expedition danishingolfex5bpt5a8daniuoft Year: 1899-1953 138 HYDROIDA II Hydrallmaniafalcata has its chief occurrence in the littoral region of the boreal seas, and may exceptionally penetrate deeper down into the abyssal, where it has, however, once or twice been ob- served at 2000 metres depth. The species can move right up into arctic waters, and has even been met with in the Kara Sea; otherwise, its occurrence coincides with the presence of warmer currents in the high arctic areas. It may also penetrate some distance to the southward, as is shown by its more sporadic occurrence in the Bay of Biscay. In the North Atlantic also, it has been found off the east coast of America. It is thus the more surprising that it should never have been recorded from Greenland (fig. LXXIV) as it is one of the most common of all species in Iceland waters; on the west and east coast especially, the finds were so numerous that it was impossible to note them all on the . i OQO m Fig. LXXIV. The distribution of Hydrallmania falcata in the Northern Atlantic. In the hatched regions the Hterature notes a common occurrence. chart. On the north coast of Iceland, Hydrallmania falcaia is quite sporadic in its occurrence, and is not particularly numerous on the south coast. Between Iceland and the Faroe Islands, and on the northern side of the latter, it is again fairly numerous, while in the North Sea area and along the coast of Norway it appears as a character form. Gen. Thujaria (Fleming). Upright colonies with imbedded hydrothecfe. The hydrothecEC are of bilateral structure; tlie aperture is furnished with an abcaulinally fixed single opercular plate or membrane, attached to the margin of the hydrotheca, as a rule in a more or less pronounced sinus. The polyp has an abcauline strongly developed blind sack.