180 DR. J. E. GRAY ON THE TORTOISES. [Mar. 11, 
Tribe II. Sravroryprna. Sternum cross-like, middle portion 
narrow, covered by the abdominal plates, and extended to 
the thorax; the front and hinder lobes often moveable on the 
central fixed one. Axillary and inguinal plates large; sternal 
plates 7; the gular, humeral, and pectoral plates of each side 
united ; the femoral and anal small, united into one large ventral 
shield. 
3. Sraurotypus, Wagler; Gray, P. Z.S. 1864, p. 127. 
Sraurotypus saLvini. (Fig. 5, p. 179.) 
4, Sraurrmys, Gray, P. Z. 8. 1864, p. 127. 
Tribe II]. ARoMocHELYINA. Sternum truncated in front, nicked 
behind; sternal shields 11; gular pair united into a narrow 
linear shield. Head large ; zygomatic arch very broad, strong, 
arched. 
5. AromocuE ys, Gray, P. Z.S. 1855, p. 199,==Goniochelys and 
Omotheca, Agassiz, 1857. 
Section II. KinosreRrNa or Double-flapped Box-Tortoises. Ster- 
num broad; sternal shields 8 or 11; the short process that 
unites the sternum to the thorax covered with the elongated 
axillary and inguinal plates; front and hinder lobes of the 
sternum generally moveable on the fixed central portion. In- 
ternal nostrils anterior. Alveolar plate flat. 
Tribe 1V. KinosTERNINA. 
7. Swanka, Gray, Cat. Shield Reptiles. 
8. Kinosrernon, Fitzinger; Gray, P.Z.S. 1855, p. 398, = Thy- 
rosternon aud Platythyra, Agassiz, 1857. 
CHELYDRA SERPENTINA, Gray, Cat. Shield Reptiles, t. 40. f. 2. 
B.M. 
Skull depressed, very broad behind, crown rhombic, sides of the 
face shelving outwards; orbit very large, anterior, subsuperior on 
the shelving side of the face; the cavity for the temporal muscle 
very wide ; the zygomatic arch very broad, broader than the orbit 
and much broader than the oblong erect tympanic cavity. ‘The 
palate flat, internal nostrils in the front of the palate, the outer edge 
sharp, with a central anterior bony hook, and with a broad, flat, 
smooth alveolar plate parallel to the outer edges. The lower jaw 
moderately strong, narrow in front, with a conical central bony pro- 
cess, and with a smooth, shelving, rather concave band inside the 
sharp margin. 
A young specimen in spirits, which was brought from North 
America, and presented by Mr. Arthur Russell, F.Z.S., is very beau- 
tifully painted on the sternum and underside of the margin of the 
