It is the only member of the family found in North America .
The Rocky Mountain capshell ( Acroloxus coloradensis ) is a species of freshwater snail in the family Acroloxidae , the river limpets .
Rocky Mountain capshell is the only member of the family found in North America .
The Rocky Mountain capshell ( Acroloxus coloradensis ) is a species of freshwater snail in the family Acroloxidae , the river limpets .