Halmphora Montana Guide
Credit: Josh Stepanek
  1. Striation fine
  2. Semi-stauros
  3. Axial area narrow

Valves are semi-lanceolate. Valve ends are protracted, narrowly rostrate and bent ventrally. The raphe is located near the middle of the valve, gently arched, with proximal raphe ends with slight dorsal deflection. Axial area narrow. The central area on dorsal side forms a thickened semi-stauros extending to valve margin. Dorsal and ventral striae difficult to resolved in LM.