Published online by Cambridge University Press: 01 May 2009
In examining the remarkably fine series of examples of Cœlonautilus cariniferus, mostly from the Carboniferous Limestone of Ireland, contained in the Geological Collections of the British Museum (Nat. Hist.), some were found to exhibit upon the cast of the body-chamber distinct marks of the shell-muscles. In one specimen (No. 50190) these are so perfect as to give a very clear outline of their form, and some of the test having been removed, their entire course can be made out.
This name from κοῖλον hollow (referring to the umbilicus), and Nautilus, is proposed by one of us in substitution for Trematodiscus, Meek and Worthen, which was used by Häckel for a genus of Radiolarians. The name Trematoceras proposed by Hyatt (Proc. Boston Soc. Nat. Hist. 1883, vol. xxii. footnote, p. 291) in lieu of Trematodiscus is equally ineligible, because preoccupied, for although the species described by Eichwald (Leth. Rossica, 1860, vol. i. p. 1259)—Trematoceras discors—was a Bactrites, a generic name once publislied cannot be again employed, even for a different group, without risk of confusion.
page 496 note 1 This enlargement is not indicated in the Figure, as it should have been.
page 496 note 2 Palæontographica, bd. xvii. 1870, p. 185, plates xxxix. xl.Google Scholar
page 497 note 1 Proc. Roy. Soc. 1856–1857, vol. viii. p. 381.Google Scholar
page 497 note 2 Prof. Blake, “Brit. Foss. Ceph.“ pt. i. p. 10Google Scholar; see also “Note on the Pearly Nautilus,” by Smith, E. A., F.Z.S.. in “Journ. of Conchology” for 10. 1887Google Scholar; also ‘Catalogue Fossil Cephalopoda,’ British Museum (Nat. Hist.), pt. i. 1888, p. xi.Google Scholar
page 498 note 1 Synopsis of the Carboniferous Limestone Fossils of Ireland, 1844.
page 498 note 2 United States Geol. Survey of the Territories, 1876, vol. ix. p. 490.Google Scholar