. The Danish Ingolf-expedition. Marine animals; Marine animals; Hydrography; Hydrography; Scientific expeditions. HYDROIDA II 21 again, we find in the shape of the hydrotheca; according to Krarap, (1911 p. 376) the margin of the hydrotheca in Grammaria abietina — in contrast to Gra?nmaria immersa — always curves outwards slightly; in forma brevicyatha, on the other hand, this is only quite exceptionally the case, and by far the greater number of hydrotheca; show no indication of outward curvature in the margin. Kramp has (1. c.) pointed out another feature which is here of more importance. In
. The Danish Ingolf-expedition. Marine animals; Marine animals; Hydrography; Hydrography; Scientific expeditions. HYDROIDA II 21 again, we find in the shape of the hydrotheca; according to Krarap, (1911 p. 376) the margin of the hydrotheca in Grammaria abietina — in contrast to Gra?nmaria immersa — always curves outwards slightly; in forma brevicyatha, on the other hand, this is only quite exceptionally the case, and by far the greater number of hydrotheca; show no indication of outward curvature in the margin. Kramp has (1. c.) pointed out another feature which is here of more importance. In forma brevicyatha, the hydrotheca aperture is almost invariably turned somewhat obliquely upwards, not as in forma typtca, where the plane of the aperture is parallel with the axis of the branch, or in Grammaria immersa,. Fig. VI. Localities of Grammaria abietina (forma brevicyatha +) in the Northern Atlantic. In the hatched region the literature notes a common, although scattered occurrence. where the opening is even turned slightly downwards. In forma brevicyatha, only the few large hydro- thecse have a plane of aperture parallel with the axis of the branch. Grammaria abietina is a typical arctic-boreal species, recorded also in a single instance (Bil- lard, 1904 p. 164) from the north of France. It may at times penetrate down to great depths, as for instance at the "Ingolf" St. 92, where it reached 976 fathoms, the greatest depth hitherto recorded for this species. Otherwise it is chiefly found (see fig. VI) in the deeper parts of the littoral regions of the boreal and arctic area. Grammaria abietina is also apparently an Atlantic species; it is known from the east coast of North America, to Taimur, but has not hitherto been recorded from about Bering Strait or the Pacific. If, however, it should prove correct that Grammaria scandens Stechow is a synonym for Grammaria abietina, then it must be classed among the circumpolar Please note that these image
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