borrowed from New Latin, from Greek bélos "missile, arrow, dart" + New Latin -o- -o- -mys -mys
Note: Named by the British zoologist Oldfield Thomas (1858-1929) in "The Genera and Subgenera of the Sciuropterus Group, with Descriptions of Three New Species," Annals and Magazine of Natural History, 8th series, vol. 1, no. 1 (January 1908), pp. 1-8. No explanation for the choice of name is given.