This crustacean is known from southern California, USA, to Mexico.
In adults, the terminal antennal portion is a single large, club-shaped segment.
It typically occurs on eelgrass, Zostera marina.
In adults, the head has a large elevation that is multilobed or cone-shaped.
In adults, the abdomen and tail plate are fused into a single unit without suture lines.
An extinction-risk assessment has not been added yet.