Strong side light (here from above, from the dorsal side) shows the fine concentric striations on the shell that cut across the concentric growth lines. The growth lines are centered on the umbo, while the other striations are centered to the right (posterior to) the umbo. The foot can be seen protruding from the anterior end of the shell to the left.
Yoldia seminuda trawled from 15-18 m depth off Canoe Island, San Juan Island, WA. Captured July 1987 and preserved before photographing. The foot can be seen extending from the anterior end of the shell. (Photo by: Dave Cowles Sept 2006)
