The oval shell takes the form of the substrate it is attached to, so if the substrate is ridged the shell will be ridged. The upper valve can be white to various shades of yellow and orange. The lower valve has a hole through which a group of threads pass to attach to the substrate.
Found from the low intertidal to 30m deep under boulders, attached to other shells, on wharf piles, or debris. It can also be found on soft sediments, either singly or attached to other Jingle Shells forming a stack.
It is called Jingle Shell or Oyster because the valves are often used as wind chimes.
NZ Coastal Marine Invertebrates; Vol 1
Photo Credit: Rod Morris. Photos available from www.rodmorris.co.nz