Gna*thos"to*ma (?), n. pl. [NL., from Gr. the jaw + , , the mouth.] Zool.
A comprehensive division of vertebrates, including all that have distinct jaws, in contrast with the leptocardians and marsipobranchs (Cyclostoma), which lack them.
[Written also
Gnathostomata.]
© Webster 1913.