Key to Heterocuma (adapted from Corbera et al., 2005)

1 Dorsal plate of telsonic somite truncate posteriorly. Endopod of pleopod with narrow external process. External distal portion of basis of third maxilliped not produced, carpus straight.......................................... genus Cumopsis

- Dorsal plate of telsonic somite excavated posteriorly. Endopod of pleopod without external process. External distal portion of basis of third maxilliped produced as a prominent lobe, carpus internal dilated..................... genus Heterocuma ...2

2 Endopod of uropod distinctly shorter than peduncle.......................................................... 3

- Endopod of uropod at least as long as peduncle.............................................................. 5

3 Pereopod 2 and 3 with uniarticulate exopods.................................. H. africanum africanum Zimmer, 1920

- Pereopod 2 and 3 with biarticulate exopods................................................................. 4

4 Pereopod 1 carpus subequal to propodus....................................... H. africana intermedia (Fage, 1924)

- Pereopod 1 carpus distinctly longer than propodus....................................... H. ambrizetensis sp. nov.

5 Uropod endopod article 1 shorter than article 2.............................................................. 6

- Uropod endopod article 1 longer than article 2............................................... H. sarsi Miers, 1879

6 Pleonites without carinae........................................................... H. armatum Kurian, 1954

- Pleonites with carinae.................................................................................. 7

7 Pereonites 2 and 3 with a paired dorsal carina, anterolateral margin of carapace smooth................................................................................................ H. inerme Corbera, Trirado & Martin, 2005

- Pereonites 2 and 3 with a median dorsal carina and prominent dorsolateral and lateral carinae, anterolateral margin of carapace serrated........................................................................ H. andamani Kurian, 1954