458 



CHELONIA. 



parietals, sideways to the postfrontals and upper postorbital, and 

 behind to the posterior latero-occipitals and uppermost temporal 

 shield. Finally, the posterior latero-occipitals, subtrapezoid and 

 broadest behind, with their longest side contiguous to the postorbitals, 

 are contiguous anteriorly to the anterior latero-occipitals, and ex- 

 teriorly to the temporal shields. An accessory pair of acutely trian- 

 gular latero-occipitals may be seen pointing towards the postorbitals, 

 contiguous by their longest side to the posterior latero-occipitals, their 

 base being directed towards the temporal shields. 



The posterior rim of the orbit is formed by four plates, the three 

 upper ones subequal, subangular, rather longer than broad; the lower- 

 most, much longer than broad, and the largest of the set, extends as 

 far under the orbit as the middle of the latter aperture. The remain- 

 ing portion of the inferior rim of the orbit is formed by the maxillary 

 shield. We have already stated that the upper rim was formed by 

 the edges of the frontal and parietal plates. 



The temporal shields (or plates) are irregularly angular, unequal, 

 and variously shaped. The two anterior ones, placed in contiguity 

 with the three upper postorbitals, are the largest, and larger also than 

 the postorbitals themselves. The lowermost, placed immediately 

 behind the inferior postorbital, is next in size, elongated, and subequal 

 with the upper and posterior one, which is contiguous superiorly to 

 the posterior latero-occipital plates. Over the tympanum they are 

 moderate-sized, and smallest towards the articulation of the lower 

 jaw. The latter exhibits a large and elongated shield, along its 

 branch, and two small ones towards its articulation. There is also a 

 series of narrow and elongated submaxillary shields, which are some- 

 what injured upon the prepared specimen before us. The mental 

 shields were removed in the preparation. 



The neck and limbs were not preserved ; neither was the plastron. 

 The carapax is subcordiform, broad across the middle region, and some- 

 what contracted upon the pectoral region. The back is rounded, 

 slightly ridged. We observe the usual number of epidermic shields ; 

 five vertebral ones, and four on either side. The three middle dorsal 

 shields are much longer than broad, whilst the first and fifth are 

 broader than long; hence, differently shaped, the fifth much larger 

 than the first. The marginal shields are of moderate development, 

 and twenty-five in number. The periphery of the carapax is undu- 

 lating upon its posterior half, instead of being narrow and even, as in 



