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Webster 1913 Edition
Gnathostoma
‖
Gna-thos′to-ma
,Noun.
pl.
[NL., from Gr.
γνάθοσ
the jaw + [GREEK], [GREEK], 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
Cyclostomata, containing the lampreys and hagfishes, is now in the class of vertebrates called Gnathostomata
.]Agnatha
. The extinct ostracoderms are included in the Agnatha
. The lampreys and hagfishes were included in the marsipobranchia
in the 1913 dictionary. They are now classified as an order. –>