Male of Ocythoe tuberculata Raf. (=Philonexis catenulatus, Fer.), Mediterranean, showing three stages, A, B, and C., in the development of the hectocotylus arm; h.cy, hectocotylus still in the cyst; c'y', spoon-shaped cyst at the end of the arm when freed

Freshwater and Marine Image Bank, University of Washington Libraries Digital Collections