CiiAP. II. THE TESTUDININA. 359 



either one cuntiiuious broad blade, or a club-shaped stump, terminating in flat, spade- 

 like nails. The pelvis is long from the sacrum downward, and short from behind for- 

 ward, over the pubis and ischium ; it is wider across the hip joints than across the 

 sacrum. It will be noticed, that the dimensions of the pelvis and shoulder appara- 

 tus agree with the proportions of their regions of the body, which are both high and 

 short. The I)ones of the feet and ankles are short and close together, the last joint 

 of the four inner toes only protruding free ; these joints are covered with sharp 

 nails, narrower and more pointed than tho.se of the fore feet. There is little move- 

 ment between the bones of the feet and ankles upon one another, or upon the 

 end of the foreleg; the foot is turned forward at the ankle, and the nails turned 

 down ; and, when the mascles and skin are attached, the whole limb below the 

 knee is club-shaped, largest at the bottom, resting on a flat, round base, and having 

 four nails proti'uding forward and downward from the front part of its lower 

 edge. 



The end and sides of the front part of the head are high. The nasal region 

 is broad, and the eyes wide apart. The nasal cavity reaches back, at the top, 

 with its whole width, to the brain cavity, which is also wide here, and the two are 

 separated from one another by a thin, narrow strip of bone, which is perforated 

 by the foramen olfactorium ; below this narrow strip the prefrontals do not meet, 

 and there is a large round opening between them, above the vomer. These two 

 cavities fill the upper part of the wide space between the eyes, but below they 

 recede from one another, and the space between them is filled by the palate, 

 which is raised high up at its back end, and continues .so to the prefrontals, 

 arching somewhat on the way. The alveolar margin is turned directly down- 

 ward, and terminates in a sharp edge ; the alveolar surfoce within is occupied 

 by two other ridges, and the intervening furrows ; one of the ridges on the inner 

 edge, and one between it and the outer. The lower jaw is high, its alveolar 

 surface narrow, with sharp edges, and l)()th turned up so as to leave a trou'di 

 between, which, when the jaws are closed, fits on to the middle ridge of the 

 upper jaw. The front wall of the ear cavity does not reach so far forward, at 

 its outer edge, as in the Emydoiihe. The mastoids are short and blunt, and 

 reach no farther back than the occipital condyle, so that the hind part ol" the 

 head is broad and flattened. 



The shield is entirely covered, on the outside, with epidermal scales, and the 

 skin is everywhere more or less protected with them; and on the most exposed 

 parts they are thick and stiff", and form a continuous hard covering, much more 

 impenetrable than in the Emydoida'. The parts thus protected are the to]i and 

 sides of the head, the front surface and the edges of the front leg.s, from the elliow 

 down to the finger nails, and up a little way toward the shouldei-s, the bottom 



