Sellaphora atomoides has a higher stria density, radiate striae at the apices and is much smaller in size.
Sellaphora ventraloides is also subcapitate, but the apices are less tapered and approximately equal in width to the center valve. Sellaphora ventraloides also has a bowtie-shaped central area, with interrupted striae.
Sellaphora stroemii has rounded to barely subcapitate ends that are approximately equal in width to the center valve, as well as a bowtie-shaped central area, with interrupted striae.