Greg,

Both, Saxicavella and Byssomya (or Byssonia) are now synonims for Hiatella.

You can find some on-line pictures in Poppe's cyberconchology (look for
them under Hiatellidae): http://www.conchology.be/

Also in 'Conchas y Caracolas de Chile', http://pagina.de/conchas there are
a couple of pictures.

Hope this help,

Alfonso Pina
Málaga, Spain
www.eumed.net/malakos