Archive image from page 436 of Discovery reports (1934) Discovery reports discoveryreports08inst Year: 1934 SCYPHOMEDUSAE 373 Septal regions ('false septa ') subdividing the tentacular canals near their bases are seen in all three forms. They are present in most specimens of the wyvillei type too, where their absence would be expected according to Bigelow (1909, p. 40). As may be seen from Figs. 4 and 5 they are of great variability both in size and form, very broad and long in large, small and narrow in small individuals, leaf-, egg-, or spoon-shaped. These false septa become very clearly v
Archive image from page 436 of Discovery reports (1934) Discovery reports discoveryreports08inst Year: 1934 SCYPHOMEDUSAE 373 Septal regions ('false septa ') subdividing the tentacular canals near their bases are seen in all three forms. They are present in most specimens of the wyvillei type too, where their absence would be expected according to Bigelow (1909, p. 40). As may be seen from Figs. 4 and 5 they are of great variability both in size and form, very broad and long in large, small and narrow in small individuals, leaf-, egg-, or spoon-shaped. These false septa become very clearly visible when the subumbrellar pigment has fallen off or been taken away. I therefore do not believe that they are a specific character of great importance. Excretory organs. The system of probable excretory organs (discovered by Van- hoeffen in 1903), consisting of eight pores in each principal radius near the perradial corners of the stomach, whose position is marked by eight dark brown oval spots upon the floor of the subumbrella (figured by Maas, 1904, pi. v, fig. 38), has been ob- served by me in several specimens, mostly young ones, from Sts. 405 and 440. Pigmentation. Broch makes out that his own results, corroborating those of Bigelow, indicate that the pigmentation increases with deeper water. He possessed the freshly preserved material from the Michael Sars Expedition, all with vivid and fresh colours. Although he found the pigmentation of the individuals subject to great variation, and found every transi- tion stage between hyaline and very dark specimens, he kept four groups of a diff'erent colouring separate, limiting the stages as follows: I, only the stomach and occasionally the gonads containing mented; III, pigment covering other parts of the subumbrella too, the gonads being always visible from the exumbrellar side of the medusa; IV, the pigmentation so dense that the gonads are quite invisible from the upper side. His table 9 shows the bathy- metrical distribut
Size: 1529px × 1308px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
