Eunotia mydohaimasiae valves are similar to both E. fallax and E. valida. The valves of E. mydohaimasiae have bolder and coarser striae, similar to E. fallax valves. However, E. mydohaimasiae valves are more arched with less constriction or pinching toward the ends than E. fallax. In addition, valves of E. mydohaimasiae have rounder apices that do not recurve toward the dorsal margin in the manner of E. fallax. In comparison to E. valida, the striate of E. mydohaimasiae are occasionally slightly radial or slanted on one side of the valve rather than the striae radiating towards both apices as they do in E. valida. The shape of the distal raphe ends on the valve face of E. mydohaimasiae are similar to the raphe ends of E. valida.