As Tryon (1884) wrote in his description of the genus Julia: the shell is oblong, thick, and cordiform.
The valves are closed, the margins entire and the valves are inequilateral.
The lunule is deep circular, projecting into the interior of the right valve, the left valve is in the same place furnished with dentiform tubercles.
The hinge line is simple and arched.
The ligament is external and narrow.
There are two muscle scars which are unequal and subcentral.

These animals have two valves, and the soft parts can be completely withdrawn inside the shell.
The two valves are usually thin and translucent.

The empty valves of the shells of these animals are in some cases green, in other cases brownish-green or yellow, and in yet others, colorless.
The species Julia zebra has shells that are finely striped with brown and blotched with white.
As Tryon (1884) wrote in his description of the genus Julia: the shell is oblong, thick, and cordiform. The valves are closed, the margins entire and the valves are inequilateral. The lunule is deep circular, projecting into the interior of the right valve, the left valve is in the same place furnished with dentiform tubercles. The hinge line is simple and arched. The ligament is external and narrow. There are two muscle scars which are unequal and subcentral.
These animals have two valves, and the soft parts can be completely withdrawn inside the shell. The two valves are usually thin and translucent.
The empty valves of the shells of these animals are in some cases green, in other cases brownish-green or yellow, and in yet others, colorless. The species Julia zebra has shells that are finely striped with brown and blotched with white.
Julia (gastropod)