142 CHELONURA SERPENTINA. 



The Sternum is cruciform, narrow, rather rounded anteriorly and pointed 

 posteriorly. The gular plate is single, and of rhomboid form, rounded in front 

 and pointed behind, where it is received between the brachial, which are elongated 

 and triangular, with their apices forward and truncate. The thoracic plates are 

 largest of all, and are very regularly pentagonal, with their posterior and external 

 border shortest where they join the abdominal plates, which are irregular in form 

 as well as in position; they are shaped somewhat like an hour-glass, broader 

 internally, where are two articulating facets for junction with the thoracic and 

 femoral plates; they are narrow in the middle, and again expand at the wings to 

 join with two supplemental plates; the femoral are similar to the thoracic in form, 

 but are smaller and narrower on their anterior and external border, where they 

 unite with the abdominal plates; the sub-caudal have the form of regular isosceles 

 triangles, with their bases forward and their apices backward. There are three 

 supplemental plates at the wings; the inguinal is broad, very irregularly four- 

 sided, with its posterior and external angle greatly prolonged; the axillary is also 

 broad, and is regularly quadrilateral: these two unite the abdominal with the 

 marginal plates by means of a cartilaginous substance. The third supplemental 

 plate is situated in front of the axillary; it is long, narrow, and pointed anteriorly, 

 but is in no way connected with the abdominal plates. 



The head is very large, yet the animal can draw it under the carapace; it is 

 broad behind and flattened above, with the snout short, though pointed, covered 

 posteriorly vdth warty integuments, and anteriorly with the same and occasional 

 small plates at the sides, all adhering firmly to the cranimii. The nostrils are 

 anterior and near together. The eyes are large, prominent, and placed near the 

 snout; the pupil is dusky, the iris grey, with a few specks of yellow. The upper 

 jaw is strong, with a sharp cutting edge and a well developed hook in front, on 

 each side of which is a depression or notch. The lower jaw is equally firm, with 

 a similar cutting edge, an equally well developed hook in front, and is received 

 witliin the upper. The neck is long, but thick, and covered both above and 

 below with a granulated or warty skin, and occasional warts of larger size, two 

 of which, at the chin, are of great length, like barbels. 



