[19] Recent literature has thrown some doubt upon its occurrence in Western Europe.
[20] It is quite possible this may refer to the relatively modern incursion of Norsemen and other Europeans into America by the North Atlantic.
Many other bibliographical references have been added in the text while this memoir was in course of printing.
=1.= D’ALBERTIS, L. M. “New Guinea.” London, 1880, Vol. I.
=2.= ALLEN, F. A. “The Original Range of the Papuan and Negritto Races.” _Journ. Anthropol. Inst._, Vol. 8, 1878-9, p. 38.
=3.= BANCROFT, H. H. “The Native Races of the Pacific States of North America.” London, 1875.
=4.= BENT, T. “The Bahrein Islands in the Persian Gulf.” _Proc. R. Geograph. Soc._, 1870, p. 13.
=5.= BLACKMAN, A. M. “The Significance of Incense and Libations in Funerary and Temple Ritual.” _Zeitsch. f. Ægypt. Sprache_, Bd. 50.
=6.= BREASTED, J. H. “A History of Egypt.” London, 1906.
=7.= BROWN, J. MACMILLAN. “Maori and Polynesian.” London, 1907.
=8.= BUCKLAND, A. W. “The Serpent in Connection with Primitive Metallurgy.” _Journ. Anthropol. Inst._, Vol. 4, 1874-5, p. 60.
=9.= _Ibid._ “Ethnological Hints afforded by the Stimulants in use among Savages and among the Ancients.” _Journ. Anthropol. Inst._, Vol. 8, 1878-9, p. 239.
=10.= _Ibid._ “On Tattooing.” _Journ. Anthropol. Inst._, Vol. 17, 1887-8, p. 318.
=11.= CAPART, J. “Une Rue de Tombeaux.” _Brussels_, 1907.
=13.= _Ibid._ “The Rude Stone Monuments of India,” _Proc. Cotteswold Naturalists’ Field Club_, Vol. XV., May, 1905, p. 117.
=14.= DAVIDS, T. W. RHYS. “Buddhist India.” London, 1911.
=15.= ELLIS, W. “Polynesian Researches.” Vol. I., London, 1832.
=16.= ENOCH, C. R. “The Secret of the Pacific.” London, 1912.
=17.= FERGUSSON, J. “Rude Stone Monuments in all Countries.” London, 1872.
=18.= FEWKES, J. WALTER. “Great Stone Monuments in History and Geography.” Presidential Address delivered before the Anthropological Society of Washington, February 20th, 1912.
=19.= FLOWER, W. H. “Illustrations of the Mode of preserving the Dead in Darnley Island and in South Australia.” _Journ. Anthropol. Inst._, Vol. 8, 1878-9, p. 389.
=20.= FOX, A. LANE. “Remarks on Mr. Hodder Westropp’s Paper on Cromlechs, with a Map of the World, shewing the Distribution of Megalithic Monuments.” _Journ. Ethnol. Soc._, Vol. 1, 1869, p. 59.