Stauroforma Exiguiformis Guide
Credit: Eduardo Morales, Sarah Spaulding
  1. Apices broadly rounded
  2. Sternum narrow
  3. Spines aligned with costae
  4. Mantle striae reduced

Valves have broadly rounded ends. The sternum is narrow. Spines are round, hollow and positioned on the costae. Apical pore fields are absent. In girdle view, frustules are rectangular and striae on the mantle are reduced.