Gomphonema Eileencoxiae Guide
  1. Valves slightly dorsiventral
  2. Valves large
  3. Apices narrowly rounded to apiculate
  4. Central area transversely rectangular
  5. Stigmoid present

Valves are large (60-90 ┬Ám long), rhombic-lanceolate and slightly dorsiventral. Apices are narrowly rounded to apiculate, without much difference between headpole and footpole, that is, the valves are nearly isopolar. The central area is transversely rectangular with one long stria on the dorsal side and one very short stria on the ventral side. A single stigmoid is present at the end of the longer stria.