The aboral side of the central disk looks inflated and has many scattered scales. The radial shields are paired at the base of each ray and in contact with each other for most of the length except for at the end nearest the center of the disk, where they are separated by a thin line of scales. Aboral view of arm. The aboral plates on the rays are oval and wider than long. The arm spines taper to a point and are nearly round. Tube feet can be seen projecting below arm.
Amphioidea urtica found intertidally in mud at Padilla Bay, June 2012 by Sarah Bewley and Melissa Moxey. Central disk is 9 mm diameter and total span is about 15 cm. Note that several arms are regenerating and others have recently broken but have not yet started regeneration. (Photo by: Dave Cowles, June 2012)
