. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. SCYPHOMEDUSAE 383 The GASTRO-VASCULAR SYSTEM of Atollo chimi (Figs. 8 «, Z>) agrees on the whole with the descriptions given by Vanhoeffen (1903) for A. valdiviae, by Maas (1903, 1904) for bairdi and by Bigelow (1909) for ivyvillei, but there are differences enough to dis- tinguish A. chiini from other species of the genus, even with the naked eye. The rhopalar canals and tentacular pockets are here strongly pigmented. The rhopalar canals are thickened locally in their outermost part and beco
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. SCYPHOMEDUSAE 383 The GASTRO-VASCULAR SYSTEM of Atollo chimi (Figs. 8 «, Z>) agrees on the whole with the descriptions given by Vanhoeffen (1903) for A. valdiviae, by Maas (1903, 1904) for bairdi and by Bigelow (1909) for ivyvillei, but there are differences enough to dis- tinguish A. chiini from other species of the genus, even with the naked eye. The rhopalar canals and tentacular pockets are here strongly pigmented. The rhopalar canals are thickened locally in their outermost part and become thinner again in the neighbourhood of the rhopalium. Besides this a large subumbrellar papilla lies in the middle above each rhopalar canal. In young specimens (Fig. 8 a) this is shaped like a ball or egg, and in older ones (Fig. 8 b) distally elongated to form a rounded longitudinal ridge, which diminishes in height towards the margin. Beneath this papilla the otherwise dark rhopalar canals are very poor in pigment and become nearly transparent, so that they are visible only by their outlines. The sudden thickeningof the rhopalar canals, combined with the bright transparent oval spot formed by the papilla and the dark purple-brown pigmentation around it, gives its own cachet to the gastro-vascular system of A. chuni. In the tentacular pockets the false SEPTA, as already observed by Maas in A. bairdi and by Bigelow in zvyvillei, can almost always be observed. They are very variable in form and size, being long, short, broad, or narrow. There is such great variability of these septal regions subdividingthe tentacular canals that they do not prove to be of any systematic value as believed by Maas. The small and narrow vessels in the lappet pouches reach very far into the lappets so that at their distal ends only a small piece of the endoderm lamella is still visible. For comparison I give here two figures of the gastro-vascular system, the first showing that of a young specim
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