A most interesting case of distribution is that of the pretty little Toad so well known on the Continent under the name of "fire-toad" (_Bombinator igneus_). Though some authorities, such as Boulenger, recognise only one form of _Bombinator_,[1] others are of opinion that two well-marked varieties exist in Europe. These are looked upon by Dr. von Bedriaga as good species, but he acknowledges that they are rather critical and difficult to identify. No other species of _Bombinator_ occur in Europe. _Bombinator pachypus_, the western race,--or if we choose to call it species,--occurs in France, Germany, Switzerland, Austria, Sicily, and Greece. _B. igneus_--the eastern race--is found in Southern Sweden, Denmark, Germany, Austria, and Russia. The latter has therefore a more northerly and easterly range. The species is not known from Siberia, but makes its appearance again in China in a form which, according to Dr. von Bedriaga, does not quite agree with either of the two European races. Now if we supposed _Bombinator_ to have originated in Europe, its absence from the British Islands, most of the Mediterranean islands, and the greater part of Scandinavia would not be easy of explanation, while as an Asiatic migrant the European range is more readily understood. Its apparent absence from Western Asia might quite likely be due to the fact that the zoology of that part of the Continent is only now being investigated. The latter has, moreover, undergone great physical changes in recent geological times. The supposition that one migration of _Bombinator_ from the south-east has taken place, and then another from the east, seems to explain this case of distribution, as other similar ones, in a most satisfactory manner.