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

chap, x.] THE PAL.EARCTIC REGION. 219worms, and leeches ; it swims well, and remains long underwater, raising the tip of the snout, where the nostrils aresituated, to the surface when it wants to breathe. It is thuswell concealed ; and this may be one use of the developmentof the long snout, as well as serving to follow worms intotheir holes in the soft earth. This species is confined to therivers Volga and Don in Southern Eussia, and the only otherspecies known inhabits some of the valleys on the north sideof the Pyrenees. In the distance are wolves, a characteristicfeature of these wastes.Birds.—But few genera of birds are absolutely restricted tothis sub-region. Podoces, a curious form of starling, is the mostdecidedly so ; Mycerobas and Pyrrhospiza are genera of finchesconfined to Thibet and the snowy Himalayas ;Leucosticte, anothergenus of finches, is confined to the eastern half of the subregionand North America ; Tetraogallus, a large kind ofpartridge, ranges west to the Caucasus; Syrrhaptcs, a form ofsand-grouse, and Leriva (snow-partridge), are almost confinedhere, only extending into the next sub-region ; as do Grandalo,and Calliope, genera of warblers, Uragus, a finch allied to theNorth American cardinals, and Crossoptilon, a remarkable groupof pheasants.Almost all the genera of central and northern Europe arefound here, and give quite a European character to the ornithology,though a considerable number of thespecies are different.There are a few Oriental forms, such as Abrornis and Larvivora(warblers) ; with Ceriornis and Ithaginis, genera of pheasants,which reach the snow-line in the Himalayas and thus just enterthis sub-region, but as they do not penetrate farther north, theyhardly serve to modify the exclusively Palsearctic character ofits ornithology.According to Middendorf, the extreme northern Asiatic birdsare the Alpine ptarmigan [Lagopus mutus); the snow-bunting(Plectrophanes nivalis) ; the raven, the gyrfalcon and the snowyowl.Those which are characteristic of the barren " tundras,"but which do not range so far north as the preceding are,—thewillow-grouse (Lagopus albus); the Lapland-bunting (Plectrophanes