Cryptothallus is a previously recognized genus of liverworts in the family Aneuraceae.
The plants are small, and are white to pale green as a result of lacking chlorophyll.
[1] The morphology of species assigned to Cryptothallus is very similar to that of Aneura.
"[2] Wickett and Goffinet argued the same position on the basis of sequences of nuclear, mitochondrial, and plastid DNA, and moved Cryptothallus mirabilis to Aneura.
[3] A 2010 molecular phylogenetic study confirmed the position of Cryptothallus within Aneura.