The Natterjack Toad (_Bufo calamita_) has a very local distribution in the British Islands. In Ireland it is found only along the coast of Dingle Bay in County Kerry, where it is known among the peasantry as the Black Frog. There is no doubt about its being indigenous there, and though it has not spread beyond the very limited area of its habitat, the Irish climate cannot be said to be unsuited to its existence. Yet it seems to be extremely difficult to acclimatise it elsewhere, for though no less than sixty specimens were turned out in Phœnix Park, Dublin, about forty years ago, none of them were ever seen afterwards. They were placed in the vicinity of one of the lakes, so as to give them ample scope for breeding and developing the young, and in surroundings which were considered eminently suitable at the time. It has occasionally happened, too, that animals are introduced by kindly-disposed persons with the view of adding a species to their fauna, in complete ignorance of their previous existence in the country where they wished to naturalise them. Thus we are told that in the year 1699 one of the Fellows of Trinity College, Dublin, procured Frog's spawn from England in order to add that amphibian to the Irish fauna. It was placed in a ditch in the College Park, whence the species is supposed to have gradually spread all over the island. This story is quoted by many writers as the true history of the Frog in Ireland, and is given as an example of the rapidity with which animals spread. Unfortunately the would-be introducer seemed unaware that, according to Stuart's _History of Armagh_, the first Frog which was ever seen in Ireland made its appearance in a pasture field near Waterford about the year 1630, that is to say, seventy years before its introduction in Dublin.[5] But even Stuart was mistaken in supposing that no Frog had ever been seen in Ireland before, since Giraldus Cambrensis, in his _Topography of Ireland_, mentions that a Frog was found in a meadow near Waterford in the year 1187. Certain British species of vertebrates are generally looked upon as introduced species, though we cannot trace any record of their first establishment, and it is quite possible that, though there was local extinction and subsequent local re-introduction, they are truly indigenous and may never have become totally extinct. Such are, for instance, the Rabbit (_Lepus cuniculus_) and the Pheasant (_Phasianus colchicus_). The latter certainly had become naturalised in England before the Norman invasion.