Tijpe of the Genus Massospondylus. 113 



The fragment of tlie shaft showing the lateral trochanter 

 appears to belong to a smaller individual. It shows that the 

 trochanter was longitudinal, compressed, and directed down- 

 ward to a depth in that specimen of about yo inch, recalling 

 the condition in PaUeosaurus and Zanclodon. 



The distal fragment at its proximal extremity is 2 inches 

 wide, and rather thicker, owing to the breakage occurring at 

 the base of the lateral trochanter. The bone widens distally 

 to 4 inches. The external border is rather more concave 

 than the internal border. The thickness is about ly^ inch 

 where the elevation below the trochanter has subsided ; but 

 at the distal extremity the development of the condyles gives 

 the bone a thickness of ^y^o inches. The distal condyles are, 

 as usual, a large internal, vertically ovate, prominent process 

 and a smaller external condyle, external to which is the 

 usual oblique external infero-lateral area, though much less 

 compressed than usual, so that it produces a convex inflation 

 of the external distal side of the bone. There is a deep 

 groove between the two condyles, and this divides the distal 

 articular end in a broad U-shape into two nearly equal but 

 unsymmetrical parts. In this respect also the bone is inter- 

 mediate between Palceosaurus and Zanclodon. 



The Tihia. (Bigs. 8 and 9.) 



The bone no. 363 is the proximal end of a right tibia (fig. 8) 

 more perfect than 365, which is the corresponding proximal end 



Fis. 9. 



Fig. 8. 



Fig. 8. — Proximal eud of right tibia, seen from above. 



Fig. 9. — Anterior aspect of the distal end of the left tibia. -| nat. size. 



of the left tibia ; 364 is the distal end of a left tibia (fig. 9), 

 probably from the same individual as 365. On the hypothesis 

 Ann. <& Mag. N. But. Ser. 6. Vol. xv. 8 



