Carapace
Orthoconchoecia bispinosa
Halocyprid carapace
The carapace consists of two valves that are hinged along the dorsal line. Their shapes range between being quite globular, to being cylindrical or laterally compressed. The carapace shapes and dimensions show marked sexual dimorphism in adults, and there are allometric differences between the larval instars.
The surface of the carapace can be smooth or incised with longitudinal or concentric striae or covered with elaborate sculpturing of lines and rectangles and even spines.
