This pair of individuals, which includes the individual shown at the top of the page, were both on the same anenome. Though I did not check thoroughly, I did not see ovigerous legs on either individual suggesting they are both female.
Pycnogonum stearnsi from Little Corona del Mar, CA. Total leg span about 1 cm. Animal was in a tidepool next to the base of an Anthopleura sola anemone. The head with its large proboscis is facing left (there is a bubble at the tip of the proboscis) (Photo by: Dave Cowles, November 2006)