Japan, Hawaii, Midway Atoll, Raratonga and Magaia (Cook Islands). Probably widespread at least in the tropical Pacific.
Live animal 2.5 mm long, from algae wash at Napili Bay, Maui, Hawaiian Ids, July 3, 1996. Depth less than 1.5 m. Shell 2.9 mm long. From beach drift at Makuleia Bay, Maui in 1983. Photos: Cory Pittman
The color is highly consistent with narrow, continuous brown bands on the anterior portion of the shell and broader, fainter bands on the posterior portion. The bands are superimposed over random white blotches. In live animals, there is extensive brown pigment on the head and rhinophores. The hinge is relatively small and constricted. The central, tooth-like knob is nearly circular in cross section with only a slight indentation on its posterior margin.
It might ultimately turn out to be a synonym of J. thecaphora Carpenter, 1857. Beach-worn shells of that species from the Gulf of California housed at the California Academy of Sciences appear indistinguishable from Hawaiian shells of J. zebra.
• Kawaguti, S (1981) A new bivalved gastropod Julia zebra. Bulletin of the Kawasaki Paramedical College, 1: 9-13.
Pittman, C., 2001 (October 10) Julia zebra Kawaguti, 1981 . [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/julizebr