M: TRTARSIO ICITTITYOSAUmA. 121 



nearly complete specimen, no. 9950. In specimen 9947 (pi. 12) a pelvic limb is 

 present in whi.-h the femur has the same form and almost the same dimensions 

 as in no. 9950. 



The hind limb of no. 9947 shows the propodial and epipodial elements in 

 their natural positions in the matrix, and with them are two small elements 

 from the distal half of the paddle. 



The /'nit <ir. is more slender than that of Delj>lih/ox<iiir/<x. Ton'tociinmiH, or 

 The nearest approximation to this type is found in Mi.roxminix, 

 but even here the distal expansion is relatively greater. 



On the upper side of the femur the plane of the flattened distal end is 

 continued over the proximal end with but little elevation. On the lower side 

 of the proximal end a heavy trochanteric ridge is developed. 



The distal end of the femur shows a broad terminal facet extending across 

 nearly its whole* width, and situated normal to the long axis of the bone. On 

 this large facet the tibia articulates, standing in such a position that its long 

 axis falls into a line almost coinciding with the long axis of the femur. Behind 

 the broad terminal face of the femur there is a smaller facet standing almost 

 normal to the plane of the terminal facet. 



The tibia is longer than its greatest transverse diameter, and its proximal 

 diameter is considerably greater than the distal. The median region is strongly 

 constricted. The anterior side of the distal end is not expanded laterally be- 

 yond the. limits of the median or shaft portion of the bone, but ends abruptly 

 in a flat, roughened or pitted facet. Whether a small element has articulated 

 on this face is as yet not certainly known. 



The fibula articulates on the small posterior face of the femur, the situation 

 of the bone being such that it is articulating largely against the posterior side 

 of the femur with its narrower end. The median portion of the fibula is con- 

 stricted. The distal end of the bone is greatly broadened compared with the 

 transverse extent of the proximal and median portions, and shows a strongly 

 curved terminal margin. 



Of the other two elements present with the limb in specimen 9947, one is a 

 small discoidal bone situated between the distal ends of the tibia and fibula, and 

 presumably representing a mesopodial. The other bone is larger and is situated 

 near the distal end of the fibula, but its form is too indefinite for determination. 



The size and relative length of the epipodial elements of the posterior limb 

 of specimen 9947 are much the same as in the elements of the corresponding re- 

 gion of the anterior limb of specimen 9950. Both epipodials show, however, a 

 somewhat stronger median constriction than is seen in the anterior epipodials. 



The most peculiar feature of the posterior limb is the situation of the tibia 

 almost opposite the middle of the distal end of the femur, with the fibula 

 located far back, and practically articulating on the posterior side of the femur. 



