I. CHELYDRA. — 2. MACROCI.KMMYS. 



23 



_Tlie largest spociraeii in the Collection measures : — Head and neck 

 25 ceiiiim., carapace ^55, tail 30. 



Xorth America, cast of the Eocky Mountains, from Canada to 

 Mexico : Ecuador. 



n, o, p. Ad. & Ilgr., .stfl'd. 

 q, r. Ilgr. & yg., spir. 

 s, t. Ilgr., skel. 

 u. Skull. 



Lake of Woods. 



Grosse Id., Michigan. 

 Grosse Id., Michigan. 

 Blooniington, Indiana. 



Meadville, Pennsylvania. 

 Independence, Missouri. 

 Typeo Spi'ings,Tennessee. 

 Louisiana. 

 New Orleans. 

 N. America. 



N. America. 



N. America. 

 N. America. 



N. America. 

 N. America. 



G. M. Dawson, Esq. 

 rC.]. Brit. N. A. 

 Boundary Comm. 



Smithsonian Inst. 

 Smithsonian lust. 

 C. II. Bollman, Esq. 



Smithsonian Inst. 

 Smithsonian Inst. 

 Smithsonian Inst. 



M, Sall^ [C.]. 

 Lord A. Russell 



[r.]. 



Gen. Ilardwicke 



[P.]. 



, • 2. Chelydra rossignonii. 



Emysaurus rossignouii, Bocourt, Miss. Sc. Me.r., Rent. \). 18, pi v 



fig. 2 (1870). 

 Chelydra rossignonii, Cope, I'ruc. Ac. Philad. 1872, p. 23; Giinth. 



Biol. C.-Am., Rept. p. 10 (1885). 



This species, which is known only from young specimens, appears 

 to be intermediate between G. serpentina and the fossil C. murchi- 

 soiiii. From the former, it differs in the much broader bridge, 

 which measures hardly one seventh of the length of the plastron ; 

 abdominal scutes not twice as broad as deep. Chin with four barbels. 



Mexico ; Guatemala. 



2. MACROCLEMMYS. 



Chelonura, part., Holhrook, N. Am. Herp. i. p. 139 (1842). 



Macroclemys, Gray, Cat. 8h. Rept. i. p. 48 (18oo). 



jNIacrochelvs, Gi-ay, Proc. Zool. Soc. 1855, p. 200 (1856), and Snpid 



Cat. Sh. Rept. i. p. 64 (1870). 

 Gypochelys, Ayassiz, Contr. A. H. U. S. i. p. 413 (1857). 

 Macroclemmys, Strauch, Chelon. Stud. p. 35 (1862). 



Three or four additional or supramarginal shields on each sidp. 

 Orbits lateral. Tail with small scales inferiorly. 

 North America. 



