TORTOISES. 39 



vided into subregular plates, especially on the temples. Jaws na- 

 ked, slender, weak. Chin 2-bearded. Hind legs with a compressed 

 scaly tubercle on the outer side, above the foot. Toes webbed. 

 Claws 5-4, acute. Shell oblong, depressed, back flattish, lateral 

 margin revolute. Nuchal plate distinct, anterior vertebral plate 

 larger than the other, often very broad. Sternum solid, not mo- 

 bile; lobes broad, the front one rounded. Tropical America. 



The Doubly Keeled Hydraspis. Hydraspis planiceps, Gray, 

 Syn. R. 40. Testudo planiceps, or platvcephala, Schneid. Berol. 

 Naturf. iv. t, 16. Schoepf. T. 115, t. 27." Schweig. Prod. 303, n. 

 16. Wagler, Sys. 135. E. platycephala, Schlegel, F. Jap. 45. T. 

 Martinella, Daud. R. viii. 344. Dum. et Bib. E. Gen. ii. 407. 

 Emys canaliculata, Spix, Bras, t. 8,/. 1, 2. Wagler, Syst. t. 4,/. 

 1 , 25. ? E. discolor, Thumb. MS. Schweig. ? E. Schoepfii, Weig- 

 mann. 



Shell quadrangular, fulvous, marked on each side of the disk 

 with a large black spot; back with two rounded keels, separated 

 by a broad groove ; costal plates not arched ; sternum black edged 

 with yellow ; head covered with a thin single plate. 



Iuhab. Brazils. Mus. Bell. 



The Rayed Hydraspis. Hydraspis radiolata, Gray, Syn. R. 



44. Emys radiolata, Mikan, Delect, t. Neuwied, Abbild. t. 



— Wagler, Syst. 165. Dum. et Bib. E. Gen. ii. 412. Hydraspis 

 planiceps, jun. Gray, Syn. R. 40. E. platycephala var. Schlegel, 

 F. Jap. var. 47. 



Shell oval-oblong, narrowed and rounded in front, rather ob- 

 tusely angular behind, keelless, brown, varied with reddish ; shields 

 concentrically and radiately striated; head covered with numerous 

 scales ; neck tubercular. 



Inhab. Brazils. Mus. Bell. 



The Grooved Hydraspis. Hydraspis Spixii. Platemys 

 Spixii, Dum. et Bib. E. Gen. ii. 409. Emys depressa, Spix, Bras. 

 4, t. 3,/. 1, 2, (not Neuweid). 



Shell oval oblong, convex, middle of the back flattened, with 

 a narrow central groove ; costal plates arched ; sternum black ; 

 head with numerous small plates ; chin 2-bearded ; neck with co- 

 nical acute spines ; the two outer toes of the fore feet small, with 

 short rudimentary claws; the lower part of the outer side of the 

 front edge of the hind legs with a compressed tubercle, formed of 

 three compressed scales. 



o. Shell and animal. From M. Clausen's collection. 



The Depressed Hydraspis. Hydraspis depressa, Gray, Syn. 

 41. Emys depressa, Mcrrem, Tent. 22, (not Spix). Neuwied, Ab- 

 bild. t. — Schinz. Rept. 43, t. 4. Platemys Neuwiedii, Dum. et 

 Bib. E. Gen. ii. 425. E. Lyrae, Reuse. E. platycephala, var. 

 Schlegel, F. Jap. 47. 



