The background colour is a creme. On the body is a narrow black-brown longitudinal line (mono = one, stichos = line , for the single line).
This middle forsal line is bordered by a white band and s light brown band.On the body are dimpleds.
There are four indistinct marginal bands (inner a yellow band, then a green band, a blue and a purple band.
Pseudoceros monostichos can found under rubble and on the reef slope.
The dimpled flatworm feeds on colonial ascidians.