1. Gnathopod 1 simple; pereopod 7, basis with prominent postero-distal spur........... Centromedon calcaratus (Sars, 1879)
- Gnathopod 1 subchelate; pereopod 7, basis lacking prominent postero-distal spur................................... 2
2. Lateral cephalic lobe strongly projecting, acute; epimeron 3 with postero-distal corner produced into an acute strongly upcurved tooth........................................................... Centromedon productus (Goës, 1866)
- Lateral cephalic lobe subacute; epimeron 3 produced into an acute tooth, not strongly upcurved........................ 3
3. Coxa 1 tapering strongly, sub-triangular; gnathopod 1 propodus sub-triangular, palmar angle obscure................... 4
- Coxa 1 tapering weakly; gnathopod 1 propodus sub-rectangular, palmar angle distinct............................... 5
4. Lateral cephalic head lobe short, sub-triangular; dactyls of pereopods 3 and 4 longer than propodus; article 4 of maxillipedal palp vestigial............................................................. Centromedon pavor (Barnard, 1966)
- Lateral cephalic head lobe produced, sub-acute; dactyls of pereopods 3 and 4 shorter than propodus; article 4 of maxillipedal palp short............................................................ Centromedon pumilus (Lilljeborg, 1865)
5. Urosomite 1 with distinct triangular acute carina............................................................ 6
- Urosomite 1 lacking distinct triangular acute carina............................... Centromedon typhlops (Sars, 1879)
6. Gnathopod 2 chelate.................................................... Centromedon mediator (Barnard, 1962)
- Gnathopod 2 minutely subchelate......................................................................... 7
7. Gnathopod 1 basis setose anteriorly; pereopods 3 and 4 dactyls subequal in length to propodus; coxa 1 concave anteriorly................................................................................... Centromedon zoe sp. nov.
- Gnathopod 1 basis with two setae anteriorly; pereopods 3 and 4 dactyls longer than propodus; coxa 1 convex anteriorly.............................................................................. Centromedon laevis (Bonnier, 1896)