Amphibia, being more adapted to a northern climate, have acquired a more special development, and thus several forms are peculiar to the North European sub-region. Most remarkable is _Proteus_, a singular eel-like aquatic creature with small legs, found only in the subterranean lakes in Carniola and Carinthia; _Alytes_, a curious toad, the male of which carries about the eggs till they are hatched, found only in Central Europe from France to the east of Hungary; and _Pelodytes_, a frog found only in France. Frogs and toads are very abundant all over Europe, the common frog (_Rana temporaria_) extending to the extreme north. The newts (_Triton_) are also very abundant and widely spread, though not ranging so far north as the frogs. The genera _Bombinator_ (a toad-like frog), and _Hyla_ (the tree frog) are also common in Central Europe. _Freshwater Fish._--Two genera of the perch family (Percidæ) are peculiar to this sub-region,--_Percarina_, a fish found only in the river Dniester, and _Aspro_, confined to the rivers of Central Europe. Of the very characteristic forms are, _Gasterosteus_ (stickle-back), which alone forms a peculiar family--Gasterosteidæ; _Perca_, _Acerina_ and _Lucioperca_, genera of the perch family; _Silurus_, a large fish found in the rivers of Cenrtal Europe, of the family Siluridæ; _Esox_ (the pike), of the family Esocidæ; _Cyprinus_ (carp), _Gobio_ (gudgeon), _Leuciscus_ (roach, chub, dace, &c.), _Tinca_ (tench), _Abramus_ (bream), _Alburnus_ (bleak), _Cobitis_ (loach), all genera of the family Cyprinidæ. _Insects--Lepidoptera._--No genera of butterflies are actually confined to this sub-region, but many are characteristic of it. _Parnassius_, _Aporia_, _Leucophasia_, _Colias_, _Melitæa_, _Argynnis_, _Vanessa_, _Limenitis_, and _Chionobas_, are all very abundant and widespread, and give a feature to the entomology of most of the countries included in it. _Coleoptera._--This sub-region is very rich in Carabidæ; the genera _Elaphrus_, _Nebria_, _Carabus_, _Cychrus_, _Pterostichus_, _Amara_, {197}_Trechus_ and _Peryphus_ being especially characteristic. Staphylinidæ abound. Among Lamellicorns the genus _Aphodius_ is most characteristic. Buprestidæ are scarce; Elateridæ more abundant. Among Malacoderms _Telephorus_ and _Malachius_ are characteristic. Curculionidæ abound: _Otiorhyuchus_, _Omias_, _Erirhinus_, _Bagous_, _Rhynchites_ and _Ceutorhynchus_ being very characteristic genera. Of Longicorns _Callidium_, _Dorcadion_, _Pogonochærus_, _Pachyta_ and _Leptura_ are perhaps the best representatives. _Donacia_, _Crioceris_, _Chrysomela_, and _Altica_, are typical Phytophaga; while _Coccinella_ is the best representative of the Securipalpes.