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. Natural history. Geology; Zoology; Botany. W. G. EIDEWOOD. The range in the number of pinnules of the plumes in the same species, and even in different plumes of the same individual, is too wide to allow of such character being utilised for purposes of discrimination. Although the two plumes of the males of C. sibogae have no pinnules, those of the neuter individuals are provided with pinnules resembling those of other species. The massiveness of the axes of the plumes of C. nigrescens is distinctive of that species, but as regards the form of the apex it is not easy to say whether in C. nig
. Natural history. Geology; Zoology; Botany. W. G. EIDEWOOD. The range in the number of pinnules of the plumes in the same species, and even in different plumes of the same individual, is too wide to allow of such character being utilised for purposes of discrimination. Although the two plumes of the males of C. sibogae have no pinnules, those of the neuter individuals are provided with pinnules resembling those of other species. The massiveness of the axes of the plumes of C. nigrescens is distinctive of that species, but as regards the form of the apex it is not easy to say whether in C. nigrescens the apex is swollen or not, it varies so much with the different degrees of extension and contraction of the plumes (c/. figs. 23 and 24, plate 5). Terminal bulbs with refractive colourless beads such as occur in C. dodeca- lophus (text-fig. 1) are met with in C. hodgsoni (figs. 31 and 32, plate 5), but there are no such swellings in the polypides of C. levinseni, in the neuter polypides of C. sibogae, nor in the adults of C. gracilis, although in the buds of the last species they occur on the first and sometimes on the second and third plumes, and occasionally persist in the adult stage (10, p. 20). In males of C. sibogae the refractive beads occur along the whole course of the two pinnule-less Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original National Antarctic Expedition, 1907-1904; Fletcher, Lazarus, Sir 1854-1921; Bell, F. J. (Francis Jeffrey), 1855-1924; British Museum (Natural History). London, Printed by order of the Trustees of the British Museum
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