The specimens from Real de Santa Maria, Tapalisa, and Cituro, average darker than all others, but this darkness is approached in certain specimens of _griseus_ (for example, No. 139833, from Vijagual, San Carlos). The broader, more rounded and less acutely pointed squamosal arm of the zygoma supposedly characteristic of _ignavus_ is matched in certain specimens of _griseus_ (for example, in No. 2824 from Juan Viñas, Costa Rica) and the character is variable among specimens referred to _ignavus_; the shape of the squamosal arm is of doubtful taxonomic worth in the present connection. The depth of the grooving on the palate seems to vary with age and is of questionable value taxonomically. The emarginate nasals of _ignavus_ are matched in _griseus_ (No. 139833) from Vijagual, San Carlos, Costa Rica. The extension of the anterior symphyseal region of the mandible is short in _ignavus_; the specimen with the longest extension (No. 37621 from El Real), however, has the extension only barely shorter than does No. 139933 of _griseus_ from Vijagual, San Carlos, Costa Rica. In brief, while we see the characters of _ignavus_ as set forth by Goldman (_op. cit._), we find them to be of only an average sort and not pronounced. Further, a specimen (No. 139833) from Vijagual, San Carlos, Costa Rica, provides a morphological intergrade between _griseus_ and _ignavus_. Accordingly, we arrange _ignavus_ as a subspecies of _griseus_; the name of the animal from extreme eastern Panamá should stand as _Bradypus griseus ignavus_ Goldman, 1913. ~Cyclopes didactylus mexicanus~ Hollister