Source : Webster's Revised Unabridged Dictionary (1913)

Herpetology \Her`pe*tol"o*gy\, n. [Written also, but less
   properly, erpetology.] [Gr. ? a creeping thing, reptile (fr.
   ? to creep) + -logy: cf. F. herp['e]tologie.]
   The natural history of reptiles; that branch of zo["o]logy
   which relates to reptiles, including their structure,
   classification, and habits.

Source : WordNet®

herpetology
     n : the branch of zoology concerned with reptiles and amphibians