To identify Geitodoris planata, both dorsal and ventral view are important :
- the mantle is crisp, hard and brown, covered in numerous small tubercles and in stellate patterns
- in the centre of each stellate pattern of the mantle there is always a raised tubercle
- the underside of the animal is creamy white with some dark spots. The mouth and oral tentacles can be seen well

Geitodoris planata can be mistaken for Archidoris pseudoargus. Here are main differences between these species :
- G. planata is crisper, harder and flatter than A. pseudoargus
- A. pseudoargus hasn't any stellate pattern on the mantle
- the ventral view allows to see oral tentacles in G. planata, but not in A. pseudoargus

Also, Geitodoris planata looks very similar to Discodoris stellifera. They can be recognised by their radula, but I don't know the external characteristics which allow to distinguish these species.

European Atlantic