Towards the north the vegetation is palaearctic, and differs little in its composition from that of Germany, Russia and Siberia.
The mammal fauna of the Indian region of Asia is much more highly developed than that of the Palaearctic.
Madagascar has seven, and one species just enters the Palaearctic.
The genus is confined to the Palaearctic and the Nearctic regions.
As compared with shrews, amongst the smallest of palaearctic mammals, the hedgehog is of considerable size.