Tattersall, 1906
Integument thin. Head deformed, short, with frontal process (Metacyphocaris helgae 1). ANT short, ANT I attached to ventral surface of frontal process of head. Accessory flagellum of ANT I uni-articulate. MD with small smooth molar; mandibular palp rudimentary, 2-articulated, or absent. Coxae I and II small, partially hidden by CX III. P I (gnathopod I) simple, with subequal ART 5 and 6. P II simple. P III-V subchelate (Metacyphocaris helgae 3), P VI-VII clearly simple. Exopodite of UR II elongate, 2-articulated (Metacyphocaris helgae 2); endopodite very short, scale-like. Telson elongate, weakly (no more than 25 %) cleft. Purely pelagic genus.
Monotypic.
Metacyphocaris helgae Tattersall, 1906