Siphopatella walshii
General description:
This is a highly flattened, cap-shaped gastropod. Often found in pairs, the larger individual is the female.
Phylogeny:
Class Gastropoda
Family Calyptraeidae Lamarck, 1809
Siphopatella walshii (Reeve, 1859)
Ecology:
Always found living on the inside of gastropod shells occupied by hermit crabs.