DIAGNOSIS
This species is larger than Syngenes inquinatus with a wingspan of 100 to 110 mm, with a much better defined dark line along the Sc. Syngenes inquinatus has a well defined black line medially down the dorsum of the abdomen, which is lacking in S. cryptica.

TYPE DEPOSITORY
MNHN, Paris.

TYPE LOCALITY
Syntype male and female: Madagascar, Betioky, IX, 1949, Clement.

GEOGRAPHICAL DISTRIBUTION
This species is known from only a couple of scattered localities.

ELEVATION
43 m.

REMARKS
This species was originally described in the genus Synclisis, but this was not the genus of Navas, but rather one that Fraser erected (now a synonym of Fadrina). The types could not be located at the Paris Museum in 1999. In the original description Fraser mentions this species as being "clearly distinct from clementi by the black subcostal line on the forewing."