Orthonychia ascia X.-D. Qiao, 1983 † (uncertain > unassessed )
Orthonychia enorme (Lindström, 1884) †
Orthonychia extenuata Barrande, 1903 † accepted as Barrandicellopsis extenuata (Barrande, 1903) †
Orthonychia haerjawensis X.-D. Qiao, 1983 † (uncertain > unassessed )
Orthonychia heishantouensis X.-D. Qiao, 1983 † (uncertain > unassessed )
Orthonychia huangjingbaensis H.-Z. Pan, 1978 † (uncertain )
Orthonychia korotkovae Mazaev, 2019 †
Orthonychia marblecreekense Talent & Philip, 1956 †
Orthonychia parva (Swallow, 1858) †
Orthonychia pentalvea Talent & Philip, 1956 †
Orthonychia subrectum (J. Hall, 1859) †
Orthonychia yutaroi Ebbestad, 2023 †
Orthonychia zhifangensis X.-D. Qiao, 1983 † (uncertain > unassessed )