1. CHELYDKA. 



21 



Eniysaura serpentina, Diun. ^y L'ibr. ii. p. ooO, pi. xvii. fig. 1 (18;J5j; 



A. Bum. Vat. Mi'th. Jiept. p. 15 (1861) ; Bocourt, Miss. 6'e. Mex., 



Jh'pt. pi. V. Hg. 1 (1870). 

 Clic'lytlra eniaryiuata, Ayassiz, I. c. p. 417 (1857). 



Carapace rugose and with three tubercular keels iu the adult and 



Fig. 3. 



Sliull of Chelydra serpentina. 



d2 



