Key to the species of the genus Phallangothelphusa

1. Third maxilliped with ratio of the endopodal ischium and exopod lengths between 0.8 and 0.9........................ 2

- Third maxilliped with exopod as long as outer margin of endopodal ischium (Fig. 1E)................ P. zenuorum n. sp.

2. First gonopod with proximal projection of mesial process rectangular or square.................................... 3

- First gonopod with proximal projection of mesial process reduced and finger–like (Campos 2014: figs. 220A, E)................................................................................................ P. magdalenensis

3. First gonopod with end portion of distal projection of mesial process strongly recurved upwards (Campos 2014: figs. 218B–D).......................................................................................... P. juansei

- First gonopod with end portion of distal projection of mesial process not recurved upwards........................... 4

4. First gonopod with lateral process of irregular form (Campos et al. 2019: figs. 2B–E....................... P. tangerina

- First gonopod with lateral process near semicircular.......................................................... 5

5. First gonopod with angle of curvature between distal and proximal projections of mesial process near 60 o (Campos 2014: figs. 216B, E)...................................................................................... P. dispar

- First gonopod with angle of curvature between distal and proximal projections of mesial process greater than 90 o (Campos 2014: figs. 222B, E).......................................................................... P. martensis