32 DKRMATEMYDID.K. 



2. Staurotypus salvinii. 



Staiirotvpus (Staiiremvs) salvinii, (rray, Proc. Zool. Soc. 18G4. 



p. ii'i". 



StiUiremvs salvinii, Gra}/, Snppl. Cat. Sh. Jtcpt. 1. p. G5(1870); Cope, 



Proc. Ac. Pliilad. \b~'-2, p. 26. 

 Staurotypus salviuii, Bocourt, Miss. Sc. 3Ie.r., Rept. p. 22, pi. v. 



fig. 3 (1870) ; Oiinth. Biol. C.-Am., Itept. p. 11 (188o). 



maruioratus, /. v. Fischer., Arch. f. Nat. 1872, p. 26o, pi. x. 



Claudius severus, Cope, I. c. p. 24 ; Sumichrast, Bull. Soc. Zool. 



France, 1880, p. 167. 



pictus, Cope, I. c. p. 26. 



Staurotvpus (Claudius) severus, Bocourt, Journ. Zool. v. p. 387 



(187U). 



Anterior lobe of plastron semielliptic or ungnlar ; bridge narrow, 

 its diameter more than five times in the length of the plastron (5^ 

 to 7 times in females, 7| to 10 times in males), A small gular 

 shield is present or absent ; suture between the humerals the 

 longest ; abdominals much broader than long ; iaframarginal shields 

 usually not longer than broad. 



Length of carapace 1'*^ centim. 



Mexico, Guatemala. 



a. $,spir. Huamuchal, Guatemala. O. Salvin, Esq. |"C.]. 



(Type.) 

 h. Ilgr., skel. Guatemala. 



c, d,e. (5* 2, spir. Tapana, Tehuantepec. F. Sumichrast [C]. 



Messrs. Salvia & Godman [P.]. 

 /. c?)Stff'd. Tapana. F. Sumichrast [C.]. 



(/. J , shell and Tapana. F. Sumichrast [C.]. 



skull. 

 h,i,k. (5 2, shells. Tapana. F. Sumichrast [C.]. 



/. Yg., spir. Mexico. 



3. CLAUDIUS. 



Claudius, Cope, Proc. Ac. Philad. 1865, p. 187 ; Bocourt, Miss. Se. 



Mex., Repf. p. 19 (1870) ; Cope, Bull. U.S. Nat. Mus. no. 32, 



p. 23 (1887). 

 Claudius, part., Cope, Proc. Ac. Philad. 1872, p. 23. 



Differs from the preceding genus by the very slender bridge, 

 which does not expand towards the marginals, to which it is joined 

 by ligament * ; anterior lobe of ])lastron not movable. 



" Vertebral neural segments eight, the last pair of costals meeting 

 on the median line, but separated from the small posterior marginal 

 by a large penultimate shield " (Cope). 



Mexico. 



* Tliis iii(lifat(\-i a ^liaiio of both the byo- and hypoplastral bones similar to 

 that of tlic livoplastral in L'hcli/dru serpentina. 



