D Orientoecetes Just, 1983

1. Mandibular palp ordinary club shaped with vestigial article 2.................................................. 2

- Mandibular palp article 1 specialized with robust setae or flared................................................ 3

2. Antenna 1 flagellum with more than 12-15 articles; gnathopod 2 propodus with 3–4 posterior robust setae; uropod 1 peduncle with row of robust setae in female, none in male, outer ramus with lateral row of robust setae in both................................................................................................. O. orientalis (Walker, 1904)

- Antenna 1 flagellum with 7 articles; gnathopod 2 propodus with a single posterior robust seta; uropod 1 peduncle without robust setae in both sexes, outer ramus with at most a single lateral robust seta.............. O. erythraeus (Ruffo, 1959)

3. Mandibular palp article 1 apically flared into 2 sharp points..................... O. arabicus (Barnard & Thomas, 1984)

- Mandibular palp with large robust setae along margins.................................... O. spinipalpus Just, 2004