Order:Arcoida

(3-7-3-0-0-0-0-0-0-0-0-0-0)
Ref. Abbott, 1974 p 420
Amer. Fish. Soc., 1988 p 24
Bernard, 1983 p 14
Lidner, 1977 p 99
Vaught, 1989 p x,114
Vokes, 1980 p 10
Syn. Eutaxodonta; Prionodonta
Ref. Keen, 1971 p 36