Family Semelidae
I have several hundred colored Semeles with patterns in my collection which are usually listed under Purplish Semeles, Semele purpurascens (Gmelin, 1791). I will be listing the colored Semeles by the three main colors: purple, orange, and blonde(yellow/tan). My argument is that if you call a semele purple when it's obvuiously orange that it's not accurate. I understand that there is no other accepted scientific designation so I've kept that the same.
I also have a large number of white Semeles which are Atlantic White Semeles: Semele proficua, (Pulteney, 1799).
The Purplish Semele is a thin smooth oval shell about 1" to 1.5" with very fine concentric lines whose hinge points to the right slightly. It's identified by its purple color and detailed patterns around its edge. The color is purple and other colors with similar patterns are usually grouped under the Purplish title. The colors are usually orange, blonde (yellow/tan), and rarely transclucent or white.
The juvenile colored semeles (usually grouped under Semele purpurascens) may not have the eloborate concentric checkered patterns and may be primarily purple, orange or blonde. The hinge of these semeles is off-center which the hinge of the white semeles is centered which is an easy way to tell them apart.
Two Purple Semeles with checkered patterns (S. Hutchinsaon Island January 2021)
This bi-valve is related to tellins and coquintos. The purplish color varies and is sometimes reddish or orangish. Hence the difficulty in separating them by color. Here the shell is translucent:
Purplish semele mixture, translucent
Despite some overlap, it's safe to say that these semeles are different colors so I've seperated them. The main two colors being purple and orange. Below is a set of orange semeles.
A set of Orange Semeles (S. Hutchinson Island January 2021)
Othere semeles in my collection are the Cancellate Semele and Tellin Semele. The latter has a shape closer the the tellin family and has a single knob on the hinge.