1 Epimeral plate 3 posteroventral corner not produced as a hook........................... P. brevirostris Chevreux, 1920
- Epimeral plate 3 posteroventral corner produced as a hook..................................................... 2
2 Epimeral plate 3 posteroventral hook medium............................................................... 3
- Epimeral plate 3 posteroventral hook large and curved.........................................................8
3 Pereopod 7 basis posteroventral margin produced as an acute hook curved upwards..................................4
- Pereopod 7 basis posteroventral margin ordinarily produced....................................................5
4 Pereopod 7 basis posteroventral margin weakly crenulate, hook medium.......................... P. vallini ( Dahl, 1954)
- Pereopod 7 basis posteroventral margin smooth, hook large............... P. macrospinosa Valério-Berardo & Piera, 2006
5 Pereopod 7 basis exceeding the apex of ischium............................................................. 6
- Pereopod 7 basis reaching only the apex of ischium............................................................7
6 Epimeral plate 3 ventral margin straight................................................. P. abyssalis ( Pirlot, 1932)
- Epimeral plate 3 ventral margin convex........................................... P. ayutlanta (J.L. Barnard, 1964)
7 Pereopod 7 basis anterodistal corner lobe produced, densely setose....................... .. P. cinca (J.L. Barnard, 1961)
- Pereopod 7 basis anterodistal lobe not produced, not setose.............................. P. excavata ( Chevreux, 1887)
8 Pereopod 7 basis presenting large projections as strong spines.................................................. 9
- Pereopod 7 basis ordinarily serrate or crenulate..............................................................11
9 Pereopod 7 basis with strong spines confined ventrally.................................... P. latipes ( Norman, 1900)
- Pereopod 7 basis with strong spines splayed posteroventrally.................................................. 10
10 Head entire laterally......................................................... .. Pseudharpinia bonhami sp. nov.
- Head excavate laterally.......................................................... P. birjulini ( Gurjanova, 1953)
11 Pereopod 7 ischium anterodistal angle produced distally........................... .. P. cariniceps (K.H. Barnard, 1932)
- Pereopod 7 ischium anterodistal angle not produced distally....................................................12
12 Pereopod 7 merus posterior margin produced distally..........................................................13
- Pereopod 7 merus posterior margin not produced.............................................................17
13 Pereopod 6 basis posterior margin not smooth proximally, presenting blunt lobes or spine............................14
- Pereopod 6 basis posterior margin smooth, without lobes or projections.......................................... 15
14 Pereopod 6 basis posterior margin with a long acute spine proximally.................... Pseudharpinia jonesyi sp. nov.
- Pereopod 6 basis posterior margin with 3 blunt lobes proximally............... .. P. tupinamba Senna & Souza-Filho, 2011
15 Antenna 1 primary flagellum article 1 stout and elongate............................... Pseudharpinia pagei sp. nov.
- Antenna 1 primary flagellum article 1 ordinary..............................................................16
16 Mandible incisor with 2 teeth.................................................... P. dentata ( Schellenberg, 1931)
- Mandible incisor with 3+ teeth.................................................... Pseudharpinia planti sp. nov.
17 Maxilla 2 inner plate larger than outer.................................................................... 18
- Maxilla 2 outer plate larger than inner.................................................................... 19
18 Pereopod 7 basis posterior margin with 1 large projection as a spine...................... P. calcariaria Bushueva, 1982
- Pereopod 7 basis posterior margin weakly serrate/crenulate...................... P. antarctica Ren in Ren & Huang, 1991
19 Uropod 3 rami with ovoid shape........................................................... P. ovata Senna, 2010
- Uropod 3 rami ordinary................................................................................ 20
20 Epimeral plate 3 ventral margin convex................................................................... 21
- Epimeral plate 3 ventral margin with a concavity.............................. P. inexpectata Jarret & Bousfield, 1994
21 Epimeral plate 3 posterior margin sinuous.......................................... P. obtusifrons ( Stebbing, 1888)
- Epimeral plate 3 posterior margin not sinuous.............................................. P. berardo Senna, 2010