Fun from Saint Isidore

I am continuing to read through the Etymologies of St. Isidore of Seville off and on: I'm on the twelfth book of twenty. Sometimes I'm surprised by how modern he is: apparently the term "ant lion" is more than 1300 years old.
And then there's the times I'm surprised in the other direction. XII:vi:3:

Amphibia sunt quaedam genera piscium, dicta eo quod ambulandi in terris usum et natandi in aquis officium habeant. Ἀμφὶ enim Graece utrumque dicitur, id est quia et in aquis et in terris vivunt: ut phocae, corcodilli, hippopotami, hoc est equi fluviales.

Amphibians are certain kinds of fish, so called because they have the task of walking on land and swimming in water. For ἀμφὶ means "both" in Greek, i.e. because they live both in water and on land: such as seals, crocodiles, and hippos, these being river horses.

It's really impressive how much he knows and how differently he views the world.