18 TRIONYX FEROX. 



many toes, all perfectly well developed, and he might easily suppose each one 

 furnished with a nail, unless he took the pains to examine them closely. 



Dumeril and Bibron arc, I think, mistaken in supposing this animal of Bartram 

 a fictitious one. They say it represents the body and head of a Trionyx, but 

 that the feet and cutaneous appendages of the neck were taken from the Chelys 

 matamata (fimbriata). This can hardly be, for though the Chelys matamata is 

 mentioned in Barrere's Natural History of Guiana, at that time called "La 

 France Equinoxiale," yet the first figure given of it was by Bruguiere in "Lc 

 Journal d'Histoire Naturelle de Paris," for 1792, which is so good a one that it 

 has been repeatedly copied by other naturalists, as Schoepff, &;c. Now Bartram's 

 work was published in Philadelphia in 1791, consequently he cannot be accused 

 of this deception. Bartram was an honest, upright, though somewhat over 

 credulous naturalist. 



I can adopt neither the generic name Aspedonectes of Wagler, nor that of 

 Gymnopus of Dumeril; for though it might be necessary to subdivide the genus 

 Trionyx to accommodate all the species with soft shells and three nails, yet in 

 that case I would follow the example of Gray and Bell and retain the name 

 Trionyx for the typical form, as it has been consecrated by time, and apply the 

 new epithet of Amyda, or Aspedonectes, to those that vary from it in proportion 

 of parts, &c., as these should be considered as abnormal forms. 



