REPTILIA : CASEA 129 



half greater than its lesser. The upper extremity is very broad 

 from side to side with a not very deep groove in front between the 

 heavy cnemial expansion and the broad inner part of the head. 

 Anteriorly the border of the bone is very gently concave in 

 profile, posteriorly rather deeper. 



Fibula (Plate XXII, Fig. 7, 8). — The fibula is relatively short, 

 much expanded at either extremity, slender in the middle. The 

 outer border is straight or gently convex, the inner deeply concave. 

 The lower extremity is much expanded from side to side, its some- 

 what convex border squarely truncated; its anterior surface is 

 nearly flat, the posterior concave in the middle, the sides thicker. 

 The upper extremity is considerably expanded obliquely forward 

 and inward; convex on the outer anterior side, concave on the 

 inner; the anterior part thin, the posterior part thick; the upper 

 articular surface for the most part looking upward, forward, and 

 inward. 



Foot (Plate XXIII). — -Two feet, both right ones, have been 

 recovered, belonging with specimens Nos. 655 and 657. Neither 

 is quite complete, the latter having the bones very slightly smaller 

 and more slender. In both specimens the tarsus is completely 

 articulated and united with the metatarsals. In No. 655 the first, 

 in No. 657 the fourth and fifth digits have the first and second 

 phalanges also attached. Four ungual phalanges are preserved 

 in No. 657; three in No. 655. In addition there are four isolated 

 phalanges in each foot. These phalanges I have located in the 

 drawing as seems most probable, leaving four that are unrep- 

 resented, indicated in the drawing by outlines. A sign indicates 

 the joints in which there was no matrical contact. In No. 655 

 the first digit was lying in the position shown in the drawing; 

 in No. 657 the metatarsal was divaricated in the matrix, very 

 much as in the foot of Varanosaurus. 



The foot as a whole is very noticeably different from that of 

 Varanosaurus, in the relatively greater size of the tarsus and first 

 and fifth digits. The astragalus is more elongated, narrower 

 distally, and the tibial articulation is more nearly parallel to the 

 inner side; the foot was placed at a greater angle with the long 

 axis of the foreleg. The fibulare is also more elongated, and the 



