Ichthyologist :: Ichthyologist (n.) One versed in, or who studies, ichthyology..
Ichthyology :: Ichthyology (n.) The natural history of fishes; that branch of zoology which relates to fishes, including their structure, classification, and habits..
Ichthyomancy :: Ichthyomancy (n.) Divination by the heads or the entrails of fishes.
Ichthyopterygium :: Ichthyopterygium (n.) The typical limb, or lateral fin, of fishes..
Ichthyornis :: Ichthyornis (n.) An extinct genus of toothed birds found in the American Cretaceous formation. It is remarkable for having biconcave vertebrae, and sharp, conical teeth set in sockets. Its wings were well developed. It is the type of the order Odontotormae..
Ichthyosauria :: Ichthyosauria (n. pl.) An extinct order of marine reptiles, including Ichthyosaurus and allied forms; -- called also Ichthyopterygia. They have not been found later than the Cretaceous period..