Genus name introduced by the British zoologist William Elford Leach (1790-1836) in "A tabular View of the external Characters of Four Classes of Animals, which Linné arranged under Insecta; with the Distribution of the Genera composing Three of these Classes into Orders, &c. and Descriptions of several New Genera and Species," Transactions of the Linnean Society of London, vol. 11 (1815), pp. 307-400. Introduced on p. 337 (as a replacement in Birgus latro for Linnaeus's Cancer latro), the word is given no origin by Leach. Birgus is the Latin name for the river Barrow in Ireland (after Greek Bírgos, designation for the river in Ptolemy's Geography), though there is no apparent connection between the river and the crustacean that would support an etymology.
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