73 



The tibia (plate IX, figs. 1 and 2), was probably not as long as the femur but was a 

 decidedly robust bone. Unfortunately no specimens were secured associated with femora 

 that might be supposed to belong to the same individual. 



Of the two right tibioe figured on plate IX (provisionally referred to T. marginatus), 

 the one on the right, seen from behind, is considerably crushed so as to exaggerate the 

 breadth of the proximal end ; the other specimen is remarkably well preserved. 



This bone of the leg, cylindrical at mid-length, expands rapidly toward either end. 

 The longer axis of the distal end is nearly at right angles to that of the proximal end. 

 Viewed from behind, the proximal end is seen to be broadly concave, the outer side 

 consisting of a backwardly directed flange. On the inner side the head is divided into 

 two parts by a deep furrow. 



Measurements of tibia. 



M. 



Length of tiliia externally 1 018 



Length in front ' 980 



Circumference at narrowest part of shaft, just below the middle •379 



Breadth of upper extremity ■ 272 



Diameter of middle of head antero-posterioriy , , , . . •"2024 



Breadth of tarsal extremity , ■ 337 



Diameter at middle of tarsal surface ■ 123 



Ramus of lower jaw, plates III and IV, long and narrow, with teeth occupying a deep, 

 narrow chamber or magazine in the posterior two-thirds of the length. Coronoid process 

 high, rising abruptly from the outer side of the posterior end; laterally compressed 

 above, deeply excavated below posteriorly. An edentulous prolongation in front curves 

 obliquely downward and inward with a symphyseal surface at the 'inner forward end. 

 Upper and lower borders nearly parallel. Outer wall of dental chamber thick and strong, 

 with shallow, vertical, alveolar grooves occupying its inner side. Inner wall,. very thin, 

 averaging about 2 mm. in thickness, without alveolar grooves pro^jer ; seldom preserved. 

 Coronoid process below, produced backward externally as a thin plate of bone continuous 

 with the outer surface of the jaw ; on its inner side it unites with the outer alveolar wall 

 in advance of the posterior end of the dental chamber. Deutary canal leading from the 

 upper part of the posterior cavity forward between the outer surface of the jaw and the 

 dental chamber. Mandibular groove passing forward under the lower border of the 

 chamber. A row of foramina occurs on the inner side, one foramen at the base of each 

 vertical series of teeth. A number of foramina also present on the outer suface. Teeth 

 replaced from within, their keeled, enamelled surfaces of the crown inside ; occurring in 

 a vertical series of three or four near the middle of the jaw with two or three of a series 

 in use in the grinding siirface at the same time. Their lateral margins decorated with 

 small, rounded projections from near the apex downward to where the crown begins to 

 narrow again. 



Measurements of left ramus of lower jaw. 



M. 



Extreme length • 630 



Depth at middle of magazine • 09-5 



Width at base of magazine • 034 • - 



10 



