. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. HYDROIDA II 21 again, we find in the shape of the hydrotheca; according to Krani]), (1911 p. 376) the margin of the liydrotheca in CraiiDiiaria abirtina â in contrast to Grammaria i»imcrsa â always curves outwards slightly; in forma brevicyatha^ on the other hand, this is only cpiite exceptionally the case, and by far the greater number of hydrothecfe show no indication of outward curvature in the margin. Kramp has (1. c.) pointed out another feature which is here of more importance. In f
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. HYDROIDA II 21 again, we find in the shape of the hydrotheca; according to Krani]), (1911 p. 376) the margin of the liydrotheca in CraiiDiiaria abirtina â in contrast to Grammaria i»imcrsa â always curves outwards slightly; in forma brevicyatha^ on the other hand, this is only cpiite exceptionally the case, and by far the greater number of hydrothecfe 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 brcvicyatha^ the hydrotheca aperture is almost invariably turned somewhat obliquely , not as in forma typica^ where the plane of the aperture is parallel with the axis of the branch, or in Graminaria immersa,. Fig. VI. Localities of Giainmana abietina (forma brcvicyatha -|-) in the Northern Atlantic. In the hatched region the literature notes a common, although scattered occurrence. where the opening is even turned slightl>' downwards. In forma brcvicyaf/ia, only the few large hydro- thecse have a plane of aperture parallel with the axis of the branch. Grainiiiaria abietina is a t^â picaI 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. it is chiefly found (see fig. VI) in the deeper parts of the littoral regions of the boreal and arctic area. Grammaria abicfiita 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 t
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