Guide to Hantzschia amphioxys
- Valves bent and constricted at center
- Raphe on the same side on both valves
- Apices protracted
- Striae indistinctly punctate
Valves are bent and constricted at the center ventral margin. Raphe on the same side on both valves within a cell. so that the valve face is asymmetric to the apical axis. The apices are protracted, especially in larger specimens. Striae are indistinctly punctate, nearly parallel to radiate and may become curved toward the apices.