6. PLATEMYS. 227 



1. Platemys spixii, 



Emys depressa (non Men:), Spix, Test. Bras. p. 4, pi. iii. fig. 2 



(1824). 

 Platemys spixii, Dum. 8f Bihr. ii. p. 409 (1885) ; Strauch, Chelon. 



Stud. p. loi> (1862), and Verth. Schildkr. p. 114 (18(;5). 

 Hydraspis spixii, Gruij, Cat. Tort. p. 39 (1844), and Sh. Rept. i. 



p. 54 (1855). 

 Acantbochelys spixii, Graij, Ann. Sf Mag. N. II. (4) xi. p. 305 (1873). 



Carapace grooved along the vertebral line, the shields with con- 

 centric and radiating striaj ; nuchal shield twice as long as broad ; 

 first and fifth vertebrals very large, second, third, and fourth about 

 as long as broad in the adult. Plastron large, four times as long 

 as the width of the bridge, angularly notched behind in the half- 

 grown, very feebly in the adult ; proportions of the plastral shields 

 very variable. Skin of upper surface of head divided into numerous 

 small irregular shields; snout extremely short, very feebly project- 

 ing ; width of the parietal bones above a little more than the dia- 

 meter of the orbit ; mental barbels very small. Upper surface of 

 neck with large, erect, conical, soft tubercles. Limbs moderately 

 webbed, covered with squarish scales ; a fringe of enlarged scales 

 along the outer edge of the fore limb ; a much developed, com- 

 pressed, crescentic process on the inner side of the leg, formed by 

 three very large tubercles. Shell dark brown or black above and 

 below ; head and limbs uniform olive-brown above, lighter olivo 

 inferiorly. 



Length of shell 16 centim. 



Brazil. 



a. $ , stffd. Brazil. 



b. HgT., spir. San Lorenzo, Rio Grande do Sul. Dr. v. Ihering [C.]. 



2. Platemys platycephala. 



Testudo platvcephala, Schneid. Schrift. Berl. Naturf. Fr. x. p. 259, 



pi. vii. (1792). 



planiceps, Schoepf, Test. p. 115, pi. xxvii. (1792). 



martiuella, Baud. liepi. iii. p. 344 (1803). 



Emys planiceps, Sclnoeigcf. Prodr. p. 34 (1814). 



canaliculata, Spi.r, Test. Bras. p. 10, pi. viii. (1824). 



Platemys canahculata, Wagl. Si/st. Amj^h. pi. iv. figs, 1-26 (1830). 

 Hydraspis planiceps, (jrrai/, Syn. Rept. p. 40 (1831), a7id Cat. Tort. 



p. 39 (1844). 

 Platemys martinella, Dum. 8,- Bibr. ii. p. 407 (1835). 

 ? Hydraspis spixii, Tschudi, Faun. Per., Ilerp. p. 22 (1845). 

 Platemys planiceps, Graij, Cat. Sh. Rept. i. p. 54 (1855), and Supjjl. 



p. 75 (1870) ; Strauch, Verth. Schildkr. p. 114 (1865). 



Carapace very much depressed, deeply grooved along the vertebral 

 region, on each side of which is an obtuse longitudinal keel ; shields 

 feebly striated concentricall} in the adult; nuchal narrow ; fourth 

 and fifth vertebrals small. Plastron large, its lenglh about thrice 

 and a half the width of the bridge ; axillary and inguinal shields 



R 



