Isospondyli :: Isospondyli (n. pl.) An extensive order of fishes, including the salmons, herrings, and many allied forms..
Isospondylous :: Isospondylous (a.) Of or pertaining to the Isospondyli; having the anterior vertebrae separate and normal.
Plectospondyli :: Plectospondyli (n. pl.) An extensive suborder of fresh-water physostomous fishes having the anterior vertebrae united and much modified; the Eventognathi.
Plectospondylous :: Plectospondylous (a.) Of or pertaining to the Plectospondyli.