(n.) The natural history of fishes; that branch of zoology which relates to fishes, including their structure, classification, and habits.
Example Sentences:
(1) In the course of ichthyological inventory investigations in the main water-course of the Narew River the occurrence of Tracheliastes polycolpus Nordm.
Ichthyosaurus
Definition:
(n.) An extinct genus of marine reptiles; -- so named from their short, biconcave vertebrae, resembling those of fishes. Several species, varying in length from ten to thirty feet, are known from the Liassic, Oolitic, and Cretaceous formations.