2. HYDROMEDUSA. Pall 
Chelodina flavilabris, Dum. § Bibr. ii. p. 446 (1885); Guich. in 
Casteln. Voy. Amér. Sud, Rept. p. 8, pl. 11. (1855). 
Hydromedusa maximiliani, Gray, Cat. Tort. p. 44 (1844); Giinth. 
Ann. §& Mag. N. H. (5) xiv. p. 422 (1884). 
subdepressa, Gray, Proc. Zool. Soc. 1852, p. 184. 
flavilabris, Gray, Cat. Tort. p. 44, and Sh. Rept. i. p. 59 (1855) ; 
Strauch, Chelon. Stud. p. 162 (1862); Gray, Ann. §& Mag. N. H. 
(4) xi. p. 304 (1873). 
depressa, Gray, Cat. Sh. Rept. i. p. 60, pl. xxvi., and Suppl. 
p. 72 (1870), and Ann. § Mag. N. H. (A) xi. p. 803; Giinth. 1. ¢. 
. 423, 
r banke, Gebel, Zeitschr. ges. Naturw. xxvii. p.19, pl. iv. (1866) ; 
Gray, Ann. § Mag. N. H. (4) xi. p. 303. 
Carapace very much depressed, with a single obtuse keel, which 
disappears in the adult ; dorsal shields concentrically striated in the 
Fig. 54. 
2 ENSUES MRNA ITEM 
Shell of Hydromedusa tectifera. 
young, smooth in the adult ; nuchal shield very variable in shape 
and in size, either narrower or broader than the first vertebral, pro- 
portionally larger in the young, in which it nearly equals in length 
the latter shield. Plastron large, notched behind, with narrow 
Q 
