Agnatha

[ ag-nuh-thuh ]

/ ˈæg nə θə /

the class of vertebrates comprising the lampreys, hagfishes, and several extinct forms, having no jaws or paired appendages.

Origin of Agnatha

1875–80; < New Latin, equivalent to Greek a- a-⁶ + -gnatha, neuter plural of -gnathos -gnathous

Radula with elongated and pointed teeth, like those of the Agnatha; a jaw present.
Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 5|Various