MORPHOLOGICAL REVISION 99 



The humerus has the upper and lower ends expanded and turned almost at 

 right angles to each other; the articular surfaces are well formed. There is a promi- 

 nent entepicondylar process and a good-sized entepicondylar foramen. The ectepi- 

 condylar process is extended into a distal hook. The hemispherical articular face 

 for the radius is almost entirely on the anterior surface of the bone. 



The radius is slightly curved, with the upper end slightly expanded and the 

 lower end wider and thinner. 



The ulna has a pronounced olecranon process. The shaft is curved, leaving a 

 considerable space between it and the radius. 



The front foot is described by Williston (67) as follows: 



"Because of the compression of the middle part of the carpus in our specimen, it 

 is impossible to be quite sure of the presence of both centralia. The radiale is much 

 broader than long, articulating with the radius, the distalia of the second and third 

 digits, and with one or possibly two centralia. The ulnare 

 is a much longer bone, articulating proximally with the ulna, 

 distally with the two inner distalia, and on the outer side with 

 the intermedium. That there is a free intermedium here, 

 as in Labidosaurus, is certain, but I can not be quite sure of 

 its extent, a part of it being apparently covered over by the 

 radius. It articulates, as in Labidosaurus, proximally with h/ 

 the ulna and distally with a centrale. Five digits are present, Z> 

 as was to be expected. The first is represented by its meta- 

 carpal only, either slightly removed from its articulation with p. 

 the radiale, or, what is more probable, with its distale lost, $ 

 or cartilaginous. In the restoration it is shown removed 



from the carpal bones as in the photograph of the hand also '^'"^ftfrwmuton. '"{' 

 given herewith (see fig. 44). The first metacarpal is the 



shortest of the five, and is only moderately expanded distally. No phalanges are 

 preserved. The second metacarpal is much longer than the first, and is much 

 constricted in its middle. It has one short phalanx articulated with it, but little 

 more than half the length of the metacarpal. Additional phalanges are not pre- 

 served, but, from its size, it seems very probable that two more, and not more than 

 two, were originally present. The third metacarpal is much like the second, but 

 is a little longer. Two phalanges are present, the first about two-thirds the length 

 of the metacarpal; the second fragmentary. There may have been a third ungual 

 phalanx present. The fourth metacarpal is the longest and stoutest of all, its 

 proximal articulation more oblique than is the case with the preceding one. The 

 first phalanx is about three-fifths the length of the metacarpal. The second phalanx, 

 much shorter and smaller, has at its tip a small fragment. There may have been a 

 fourth phalanx, though there is not much probability of it. The fifth metacarpal 

 is a little shorter than the fourth, somewhat curved and more slender. It has a 

 small and short proximal phalanx and a fragment of a distal one at its tip. In all 

 probability there were no more. It is, it is seen, impossible to say with certainty 

 what the phalangeal formula of Pariotichus was, save that quite surely it was not 

 that of the modern lizards and Sphenodon, 2, 3, 4, 5, 3. In much probability it was 



2, 3» 3' 4> (3). 2." 



The pelvis is quite primitive. The ischia and pubes are broad and plate-like, 

 lying horizontally in the body and meeting in a straight symphysis, but are not 

 suturally united (fide Williston). There is a small pubic foramen near the anterior 

 edge of the acetabulum. The puboischiadic suture is very indefinite, but apparently 

 lies just posterior to the pubic foramen. The ilium stands at an angle of about 

 fifty degrees with the pubis and ischium; the crest projected strongly to the rear. 



