Halamphora Subcapitata Guide
Credit: Jeffery Stone
  1. Dorsal margin strongly arched
  2. Hyaline area on dorsal side small, or absent
  3. Arolae dash-like
  4. Dorsal side with thickened virgae
  5. Valve ends protracted

Valves have a strongly arched dorsal margin, with with protracted valve ends. The central dorsal valve has thickened virgae, formed by internal costae. The hyaline area in the central, dorsal side of the valve is very small, or may be absent. Striae are formed by dash-like areolae.