Published online by Cambridge University Press: 01 May 2009
Of the more recent accounts of the Middle and Upper Chalk of Cambridge, only that of Jukes-Browne employs the definitions of zonal boundaries now usually accepted in England; for the most part, the horizons to which he refers the exposures are correct.
page 368 note 1 Jukes-Browne, A. J., 1903–1904, “The Cretaceous Rocks of Britain,” vols. ii, iii, Mem. Geol. Surv.Google Scholar
page 369 note 1 Fearnsides, W. G., 1904, “Geology,” in Marr and Shipley, Natural History of Cambridgeshire, 8vo, Cambridge.Google Scholar Rastall, R. H., 1910, “Cambridgeshire, Bedfordshire, and West Norfolk,” chap. v, in Geology in the Field, Jubilee volume of the Geologists' Association, 8vo, London.Google Scholar
page 369 note 2 The form usually known a Holaster planus (Mantell). Lambert, M. (1893, Bull. Soc. Sci. Yonne, xlvii, p. 41) erected for this species the genus Sternotaxis, which differs essentially from Holaster in the composition of the plastron. It is unfortunate that the name of a well-established index-fossil should have to be changed; but the awkwardness may in part be overcome by adopting the Geological Survey practice of referring to zones by the trivial name of their index-fossil.Google Scholar
page 369 note 3 Rowe, A. W., 1908, Proc. Geol. Assoc., xx, p. 301 (inter alia). Lambert, J., 1903, Mém. Musée Roy. Hist. Nat. Belgique, ii, p. 48.Google Scholar
page 370 note 1 Afterwards identified by Jukes-Browne (1903, op. cit., ii, p. 18) as Offaster sphaericus Schlüter, and used under that name as the index-fossil of the Upper Cenomanian of Yorkshire.