The inside of a Californian red abalone shell, Haliotis rufescens.
This red abalone was harvested on North California coast in May, 2005. An American quarter dollar coin (24 mm or a little under one inch in width) is included in the picture to provide scale. The picture shows the inside of an abalone shell. Note the 4 respiratory holes on the upper left hand side of the shell as viewed from below. Notice the large relatively rough spot at the center of the shell. It is the large muscle attachment scar.
The inside of a Californian red abalone shell. This red abalone was harvested on North California coast in May, 2005. An American quarter dollar coin is included in the picture to provide scale. The picture shows the inside of an abalone shell. Note the