The geographical distribution of animals, with a study of the relations ...

;chap, xi.] THE ETHIOPIAN REGION. 2712 genera, Notioxerms and Homceodera, which are altogetherpeculiar and isolated, and contain 9 species.Thus no less than27 species, or more than half of the undoubtedly indigenousbeetles, belong to 5 peculiar and very remarkable genera ofEhyncophora.It appears from this enumeration, thatthe peculiar species asa whole, exhibit most affinity to the Ethiopian fauna ; next tothe South European fauna ;and lastly to that of the islands ofthe North Atlantic ;while there is such a large amount of peculiarityin the most characteristic forms, that no special geographicalaffinity can be pointed out.Land Shells.—These consist of about a dozen living species, andabout as many extinct found in the surface soil, and probablyexterminated by the destruction of the forests. The genera areSuccinea, Zonites, Helix, Bidimus, Pupa, and Achatina. TheBidimi (all now extinct but one) comprise one large, andseveral small species, of a peculiar type, most resembling formsnow inhabiting South America and the islands of the Pacific.Zonites is chiefly South European, but the other genera are ofwide range, and none are peculiar to the island.The marine shells aremostly Mediterranean, or West Indianspecies, with some found in the Indian Ocean ;being peculiar to the island.Tristan d'Acunha.—This small island issituated nearly midwaybetween the Cape of Good Hope and theonly 4 or 5 speciesmouth of the LaPlata, but it is rather nearer Africa than America, and a littlenearer still to St. Helena. An island so truly oceanic and of whoseproductions so little is known, cannot be placed in any region,and is only noticed here because it comes naturally after St. Helena.It is known to possess three peculiar land birds. One is a thrush(Ncsocichla eremita) whose exact affinities are not determinedthe other a small water-hen (Gallinula nesiotis) allied to ournative species, but with shorter and softer wings, which the birddoes not use for flight. A finch of the genus Crithagra showsAfrican affinities ;while another recently described as Nesospizaaeunlim (Journ. fur Orn. 1873, p. 154) forms a new genus said toresemble more nearly some American forms.