196 ZOOLOGICAL GEOGRAPHY. [part hi. 



snakes. Of the lizards, Lacerta stiiyium (tlie sand lizard) has 

 the most northerly range, extending into Poland and Northern 

 Eussia; and Angitis fragilis (the blind or slow- worm) has almost 

 an equal range. 



Amphibia, being more adapted to a northern climate, have 

 acquired a more special development, and thus several forms 

 are peculiar to the ISTorth 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 Eurojie, 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 Bom- 

 hinator (a toad-like frog), and Hyla (the tree frog) are also com- 

 mon in Central Europe. 



Freshwater Fish. — Two genera of the perch family (Peicidae) 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 — Gasteros- 

 teidse ; Perca, Acerina and Zucioperca, genera of the perch family ; 

 Silurus, a large fish found in the rivers of Cenrtal Europe, of 

 the family Silurida3 ; Fsox (the pike), of the family Esocidse ; 

 Cyprinus (carp), Gohio (gudgeon), Zeuciscus (roach, chub, dace, 

 &c.), Tinea (tench), Abramus (bream), Allmrnus (bleak), Cobitis 

 (loach), all genera of the family Cyprinidse. 



Insects — Lepidoptera. — No genera of butterflies are actually 

 confined to this sub-region, but many are characteristic of it. 

 Parnassius, Aporia, Zeucophasia, Colias, Melitcea, Argynnis, 

 Vanessa, Zimenitis, and Chionohas, are all very abundant and 

 widespread, and give a feature to the entomology of most of the 

 countries included in it. 



Coleoptera. — This sub-regi(m is very rich in Carabid?e; the 

 genera Elaphrus, Nebria, Carabtis, Cychrus, Pterostichns, Amara, 



