ferox_ Schneider. Schweigger (1812:285) referred _ferox_ to the genus _Trionyx_ following the description of that genus by Geoffroy in 1809. _Testudo ferox_ was listed as a synonym by Geoffroy in the description of _Trionyx georgicus_ (1809a:17); Duméril and Bibron (1835:432) mentioned that the specific characters of _georgicus_ were taken from Pennant. The name _Trionyx georgianus_ presumably appears for this taxon in Geoffroy's earlier-published synopsis (1809:367). _T. georgicus_ was listed as occurring in rivers of Georgia and the Carolinas; the type locality was restricted by Schmidt (_op. cit._:109) to the Savannah River, Georgia. The two specific names _georgicus_ and _georgianus_ are regarded as substitute names and junior synonyms of _T. ferox_. Geoffroy (1809a:14-15) also described _Trionyx carinatus_, a name-combination that hitherto has been considered a synonym of _Trionyx ferox_. There is no indication from the description that _carinatus_ is applicable to _ferox_. Most comments pertain to a description of the bony carapace and plastron, which Geoffroy depicts in Plate 4. It is a young specimen judging from the small and isolated preneural; the seventh pair of pleurals is unusual in being fused (no middorsal suture), and the neurals seem large in proportion to the size of the pleurals. The anterior border of the carapace is described as having tubercles. Geoffroy listed _Testudo membranacea_ and _Testudo rostrata_ as synonyms of _carinatus_. Fitzinger (1835:127) listed _T. membranacea_, _T. rostrata_ and _T. carinatus_ as synonyms of _Trionyx javanicus_ (= _T. cartilagineus_), which was also described by Geoffroy (_op. cit._:15). Duméril and Bibron (_op. cit._:478, 482) considered _carinatus_ to be the young of _spinifer_ (_ferox_ as synonym). Gray (1844:48), however, referred _T. membranacea_ and _T. rostrata_ to the synonymy of _T. javanicus_, but considered _T. carinatus_ to be a synonym of _T. ferox_ (_op. cit._:50), an interpretation followed by all subsequent authors. _Trionyx carinatus_ is questionably listed as a synonym of _ferox_ by Stejneger (1944:27). Duméril and Bibron (_op. cit._:482) wrote that the young type of _carinatus_ is in the museum at Paris. Dr. Jean Guibé informs me in letter of September 24, 1959, that the type of Geoffroy's _T. carinatus_ cannot be found in the Natural History Museum at Paris. For the present, _T. carinatus_ is considered a _nomen dubium_. According to Stejneger (1944:27), _Trionyx brongniarti_ Schweigger is a substitute name for _T. carinatus_. I am unable to add anything to Stejneger's (_op. cit._:32) account of _Trionyx harlani_; the mention of its occurrence in east Florida indicates that it is indistinguishable from _Testudo ferox_ Schneider.