. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 372 DISCOVERY REPORTS Annular zone. In most specimens the annular zone between the circular furrow and the pedalia was distinctly visible; in a few, particularly flat ones, the annular zone was covered by the overhanging lens and therefore apparently invisible, but it was always present. In all high specimens with broad and deep coronal furrows, the annular zone is very broad. Its presence or absence, as recently shown by Bigelow (1928), is of no systematic importance, because it depends only on
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 372 DISCOVERY REPORTS Annular zone. In most specimens the annular zone between the circular furrow and the pedalia was distinctly visible; in a few, particularly flat ones, the annular zone was covered by the overhanging lens and therefore apparently invisible, but it was always present. In all high specimens with broad and deep coronal furrows, the annular zone is very broad. Its presence or absence, as recently shown by Bigelow (1928), is of no systematic importance, because it depends only on the degree of contraction of the whole medusa. If covered by the central disc in flat specimens, it is easily made visible by lifting the central disc. In several specimens I found fine radial furrows on the annular zone corresponding to the furrows on the pedalia and the notches of the central disc. Furrows on pedalia. In most specimens of the wyvillei type the furrows on the pedalia are very distinctly visible, in a few the pedalia were smooth ( St. 86). This characteristic is thus not necessarily correlated with the deep notches of the central disc. Gastro-vascular system (Figs. 4, 5). The present series oi AtoUa wyvillei diflFers in respect of the gastro-vascular system from the descriptions given by previous authors (Vanhoeff'en, 1903, for A. valdiviae; Maas, 1904, for A. bairdi; and Bigelow, 1909, for wyvillei) by a much larger amount of pigment in the canals and pockets: the canals in the lappets reach much farther distally than figured by these authors, in whose figures they reach only a little beyond the base of the lappets. The tentacular pockets are very much broader than the narrow rhopalar canals; the pigment in the tentacular pockets reaches right up to the border of the lappets. The base of the tentacles lies deeply enclosed in a sinus within the tentacular pockets. The figures of Maas (1903, pi. iii, fig. 23 and 1904, pi. iv, fig. 34), which both show broad
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