Natrix is a genus of colubrid snakes. Four species are in the genus. They are collectively called grass snakes and water snakes. However, some other snake species known as "grass snakes" and "water snakes" are not of the genus Natrix. The genus includes: \n* Natrix maura – viperine water snake \n* Natrix megalocephala – large-headed water snake (status controversial) \n* Natrix natrix – grass snake \n* Natrix tessellata – dice snake