I) Pisces — Devonian period — Exocoetus: Correct. Devonian is rightly called the “Age of Fishes.” Exocoetus (flying fish) belongs to class Pisces.
II) Amphibia — Cretaceous period — Colotes: Incorrect. Amphibians first appeared in the Devonian period and flourished during the Carboniferous period, not Cretaceous. Also, *Colotes* is a genus of reptiles, not amphibians.
III) Reptilia — Mesozoic era — Hemidactylus: Correct. Reptiles dominated the Mesozoic era, known as the “Age of Reptiles.” *Hemidactylus* is a genus of reptiles (wall lizards).
IV) Mammalia — Palaeozoic era — Felis: Incorrect. Mammals first appeared in the Mesozoic era, not in the Palaeozoic. *Felis* (genus including cats) is a modern mammal.
Hence, incorrect matches are II and IV.