Dana, 1853
ANT I inserted on anterior surface of head, flagellum with large straight ART 1, one or a few rudimentary distal ART, inserted terminally. ANT II straight, inserted on anterior or ventral surface of head, short or rudimentary. Only P I and II may be chelate or subchelate. P VII may be partly reduced. Telson free.
Three families:
Family Cystisomatidae Willemoes-Suhm, 1875
Family Paraphronimidae Bovallius, 1887
Family Vibiliidae Dana, 1853