a) DERMATEMYDID_%. 
2. Staurotypus salvinii. 
Staurotypus (Stauremys) salvinii, Gray, Proc. Zool. Soc. 1864, 
lars 
ate remys salvinii, Gray, Suppl. Cat. Sh. Rept. i. p. 65 (1870); Cope, 
Proc. Ac. Philad. 1872, p. 28. 
Staurotypus salvinii, Bocourt, Miss. Sc. Mex., Rept. p. 22, pl. v. 
fig. 8 (1870) ; Giinth. Biol. C.-Am., Rept, p. 11 (1885). 
marmoratus, J. v. Fischer, Arch. f. Nat. 1872, p. 265, pl. x. 
Claudius severus, Cope, 1. c. p. 24; Sumichrast, Bull. Soc. Zool. 
France, 1880, p. 167. 
pictus, Cope, 1. c. p. 26. 
Staurotypus (Claudius) severus, Boer Journ. Zool. v. p. 387 
(1876). 
Anterior lobe of plastron semieiliptic or angular; bridge narrow, 
its diameter more than five times in the length of the plastron (53 
to 7 times in females, 73 to 10 times in males), A small gular 
shield is present or absent; suture between the humerals the 
longest ; abdominals much broader than long ; inframarginal shields 
usually not longer than broad. 
Length of carapace 18 centim. 
Mexico, Guatemala. 
a. Q, spir. Huamuchal, Guatemala. O. Salvin, Esq. [C.]. 
(Type.) 
6. Hgr., skel. Guatemala. 
c,d,e. 8 2, spir. Tapana, Tehuantepec. BF. Sumichrast [C. ]. 
Messrs. Salvin & Godman [ P.]. 
f. 3, stfid. Tapana. F. Sumichrast [C. }. 
g. 3, shell and Tapana. F. Sumichrast [C. |. 
skull, 
hk. $ , shells. Tapana. F. Sumichrast [C. ]. 
l. Yg., spir. Mexico. 
3. CLAUDIUS. 
Claudius, Cope, Proc. Ac. Philad. 1865, p. 187; Bocourt, Miss. Sc. 
Mex., Rept. p. 19 (1870); Cope, Bull. U.S. Nat. Mus. no. 382, 
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 plastron 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. 
* ‘This indicates a shape of both the hyo- and hypoplastral bones similar to 
that of the hyoplastral in Chelydra serpentina. 
