historical literature, and their histories have consequently been muddled. In 1822, the British ornithologist John Latham listed the parakeet of Réunion (and "other parts of the same latitude") as a variety of the rose-ringed parakeet, which he referred to as Psittica torquata, based on a name coined by Brisson. In 1876, the British ornithologists and brothers Alfred and Edward Newton pointed out that the avifauna of Réunion and Mauritius were generally distinct from each other, and that this might, therefore, also be true of the parakeets. They suggested the new name Palaeornis echo for the Mauritian species (referring to Echo, a nymph in Greek mythology), while noting that it was very similar to the by-then extinct Réunion species (which retained the name Palaeornis eques). The Italian ornithologist Tommaso Salvadori united the two again in 1891, while giving only Mauritius as the habitat. In 1907, British zoologist Walter Rothschild supported the separation of the two species on account of the other birds of Réunion and Mauritius being distinct, while noting that how they differed was unknown. The American ornithologist James L. Peters listed the parakeet of Mauritius as a subspecies of the rose-ringed parakeet (Psittacula krameri) in 1937; P. k. echo. He thereby replaced the genus name Palaeornis with Psittacula, wherein he also classified other extant parakeets of Asia and Africa. In 1967, the American ornithologist James Greenway considered the parakeets of both Mauritius and Réunion to be subspecies of the rose-ringed parakeet, and found it probable that they differed from each other, unless the birds on Réunion had simply been introduced, though how was unknown. In a 1987 book about Mascarene birds, the British ecologist Anthony S. Cheke stated that the parakeets of Mauritius and Réunion apparently belonged to the same species. In the same publication (a chapter which was one of the few studies of echo parakeet biology), British conservation biologist Carl G. Jones noted that the parakeets of the western Indian Ocean were probably derived from Indian Alexandrine parakeets (P. eupatria), losing the characteristics of that bird the farther they dispersed. Jones also reported an old parakeet skin, possibly from Réunion, in the Royal Museum of Scotland, Edinburgh (a study skin catalogued as specimen NMS.Z 1929.186.2). Originally part of the collection of the French taxidermist Louis Dufresne, it was bought by the University Museum of Edinburgh (which later became the Royal Museum) in 1819, along with the rest