Herpetology (Greek 'herpien' means 'to creep') is a branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians) and reptiles (including snakes, lizards, amphisbaenids, turtles, terrapins, tortoises, crocodilians, and the tuataras).

Batrachology is a further subdiscipline of herpetology which studies amphibians alone.

Even if you haven't heard about this before, it is possible to answer the question correctly by process of elimination. As many of you know, the study of birds is called ornithology, the study of insects - entomology, and the study of all animals is known as zoology.

More Info: en.wikipedia.org