CHELONIA. 727 



margin is very slightly curved inwards, being nearly vertical in its posterior half, 

 but more downwardly shelving anteriorly. The premaxillary pit is shallow, and 

 the premaxillary foramina are situated at the anterior end of the inner margin of 

 the alveolar plate. The latter is sHghtly grooved externally and convex inter- 

 nally, and its breadth is less than one-half of the least breadth of the pterygoid. 

 The nasal canals are obliquely oval at their palatine termination, and are con- 

 tinued backwards as far as the anterior end of the large oval palatine foramen. 

 The palatine and pterygoids are slightly concave, the breadth of the pterygoid 

 contraction is equal to one-half of the interval between the anterior external 

 processes of the pterygoid. The distance between the mandibular facets of the 

 quadrates equals the length from the occipital facet to the end of the basi- 

 sphenoid, which is rather elongated and reaches to the middle of the pterygoid 

 contraction. The depression on the under surface of the basi-occipital is well 

 defined anteriorly. The occipital spine is long and nearly straight, and the tem- 

 poral area externally is rather narrow from above downwards, somewhat posteriorly 

 elongated and slightly upward bent at its hinder end. The mandible has an up- 

 wardly pointed symphysis ; the symphysial breadth is moderate, being nearly equal 

 to the height of the posterior end of the coronoid. The outside of the ramus to 

 the coronoid is concavely bevelled off. The alveolar surfaces are narrow and present 

 one groove, each rising up posteriorly to the coronoid. The latter is less than twice 

 the height of the narrowest portion of the ramus. 



The vertebral centres are rather strong and short, and there are 3 sacral and 22 

 caudal vertebrae, the tail vertebrae of the male being considerably larger and longer 

 than in the female. The first caudal transverse process is directed backwards close 

 to the ilium and behind the third, but it does not reach the pelvis. In the second 

 cervical vertebra there are occasionally two small ossicles developed at the posterior 

 extremity, one on either side of the dorsal spine. 



In females, 6"' 2 in length of carapace, the pubis and ischium are thoroughly 

 amalgamated, not even a transverse suture being visible, and the longitudinal pubo- 

 ischial suture is all but lost. In males of the same size, the pelvis is similarly 

 advanced, but the divergent anterior extremities of the pubis, which in the female 

 are separated by cartilages, are entirely united. The pubic region of the male is 

 narrower and more pointed than in the female, and the ischial border of the latter 

 is broader and less downwardly curved than in the former, and the iliac orifice 

 is broader in the female than in the male. 



The manus is broad, with short digits, and a distinct intermedium. The inter- 

 space between the radius and ulna is wide and crescentic. The 5th toe of the 

 hind foot has two phalanges, of which the last is very small. 



The tongue is densely covered with filiform papillae. The free fold external to 

 the laryngeal orifice, defines a broad triangular surface. Immediately behind the 

 hyoid arch, the oesophagus is marked by a small area of numerous wavy rugae, 

 the anterior termination and convergence of the well-marked longitudinal folds of 

 the oesophagus. There is no trace of papilliform appendages. The stomach presents 



