A new species of Asymmetrione (Isopoda: Bopyridae) infesting the hermit crab Isocheles pilosus (Holmes) in southern California by John C. Markham. Bull. Southern California Acad. Sci., 84(2): 104-108, 1985. The new species Asymmetrione ambodistorta is described and figured. It belongs among those species of Asymmetrione whose females are distorted relatively little, but is unique in the genus for having females distorted in both directions, hence its specific name. Asymmetrione ambodistorta is the first species of Asymmetrione to be described from the eastern Pacific Ocean.