Key to species of Pseudione infesting Nephropidae lobsters in the world based on adult females

1. Ventral surface of pleopods tuberculate.................................................... Pseudione nephropsi - Ventral surface of pleopods smooth....................................................................... 2 2. Coxal plates on both sides of the pereomeres 1–4............................................... P. tanimbarensis - Coxal plates only on one side of pereomeres............................................................... 3

3. Marsupium incompletely closed, maxilliped palp extending beyond the distal margin....................... P. atlantica

- Marsupium completely closed, maxilliped palp deeply inset in the distal margin not extending beyond it..................................................................................................... P. ivanklini sp. nov.