nmyzontesA class of vertebrates in which the skull is incompletely developed and there is no lower jaw. The brain is distinctly developed. The heart is also well developed, and partitioned into an auricle and a ventricle. The gills have a pouch-like form. In the adult the mouth is circular and suctorial. The Myzontes are the lampreys and hags, representing two orders, Hyperoartia and Hyperotreta. Also called Cyclostomi, Marsipobranchii, and Monorhina.
Chambers's Twentieth Century Dictionary
n.plMyzontesmī-zon′tēz a class of vertebrates with an incomplete cartilaginous skull, no lower jaw, and pouch-like gills—including the lampreys and hags
adj., nMyzontessuctorial as the lamprey, belonging to the Myzontes