Runcina sp RB1.
Found in samples of Galeolaria and Pyura taken from jetty next to the North Road boat ramp, Brighton.
Photo by Leon Altoff.
Poor image quality. Subject (found by buddy Gareth) is at centre and is very small.There were 2 in close proximity but I couldn't get useful images of the other, and it looked identical to this one apart from being about 1mm shorter.