. The Danish Ingolf-expedition. Marine animals; Marine animals; Hydrography; Hydrography; Scientific expeditions. 164 HYDROIDA II. 600 m. _ to00 m. Fig. LXXXIV. The occurrence of Camj>anularia Johnstoni in the northern Atlantic. In the hatched region a common occurrence is stated. Gen. Laomedea Lamouroux. Upright, sympodial colonies only occasionally exhibiting creeping parts with nnbranched polyp stalks. The hydrotheeee have a typical broad diaphragm which forms the boundary between the main cavity and the basal chamber. The polyps can be withdrawn entirely into the radially symmetrical hy
. The Danish Ingolf-expedition. Marine animals; Marine animals; Hydrography; Hydrography; Scientific expeditions. 164 HYDROIDA II. 600 m. _ to00 m. Fig. LXXXIV. The occurrence of Camj>anularia Johnstoni in the northern Atlantic. In the hatched region a common occurrence is stated. Gen. Laomedea Lamouroux. Upright, sympodial colonies only occasionally exhibiting creeping parts with nnbranched polyp stalks. The hydrotheeee have a typical broad diaphragm which forms the boundary between the main cavity and the basal chamber. The polyps can be withdrawn entirely into the radially symmetrical hydrothecre. The hydranth has a clnb-shaped proboscis, and homogeneous gastral endoderm. Lamouroux (1812) gave the following diagnosis of the genus: "Polypier phytoide, rameux; cellules stipitees ou substipitees, eparses sur les tiges et les rameaux". This thus embraces the up- right colonies of Camfianulariidce, but Lamouroux has nevertheless placed Campanularia verticillata in his genus Clytia. There is thus no reason to suppress the name Laomedea for later and more narrowly restricted genera, and we cannot, on phylogenetic grounds, break up the genus as here defined on account of the biological peculiarities apparent in the gonophores. Nor is a better survey obtained by dividing the genus according to the nature of the gonangia, which it is in most cases impossible to determine with certainty from the colonies obtained. And that characters should be easier to handle when raised to generic rank than when applied to species it is not easy to understand. In this genus, we find quite exceptionally that certain species, such as Laomedea dichotoma (Linne) may occur with creeping growth modification (cf. Broch 1913 p. 55); in such case, however, the diaphragm distinctly shows to what genus the species must belong. These creeping parts are. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration
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