450 GEOLOGICAL SUEVEY OF THE TEERITORIES. 



are concave ; the anterior are compressed with lenticular vertical section, 

 with angle below. The more posterior is less compressed, and the sur- 

 face is smooth ; in the anterior, it is thrown into weak longitudinal ridges 

 near the edges of the articular extremities. There are large nutritious 

 foramina on the sides. The neurapophyses aj?e excavated vertically on 

 their posterior edges. Neural arch on the anterior dorsal, a broad, verti- 

 cal oval. A caudal vertebra is rather elongate and depressed ; as it has 

 no diapophysis, it is not from the anterior part of the series. There is 

 no prominent lateral angle, but the two inferior angles connecting the 

 chevron-facets are well marked ; neurapophysis only measuring half 

 the length of the centrum. The articular faces exhibit the same trans- 

 verse fossa as is seen in the dorsals j the anterior is plane, the posterior 

 uniformly concave. 



Measurements. 



M. 



Anterior dorsal, length of centrum 074 



Anterior elevation of articular face 073 



Anterior width of articular face 070 



Anterior vertical diameter of neural canal 027 



Anterior elevation of anterior zygapopbyses 122 



Middle dorsal, length of centrum 068 



Middle elevation of articular face 085 



Middle width of articular face .- 080 



Middle caudal, length of centrum 062 



Middle elevation of articular face, (at canal) 047 



Middle width of articular face 068 



Middle width between inferior angles , 024 



Middle width of neural canal ■. 013 



The femur is only represented by the distal end, with the condyles 

 perfectly preserved. The latter form a single trochlear surface, whose 

 borders form arcs of circles. It is slightly hour-glass-shaped, chiefly 

 by excavation of the posterior face, which is, however, shallow ; the deep 

 fossae seen in Hadrqsaurus and other genera being absent. The area 

 of the articular cartilage is clearly marked out, and the dense surface of 

 the shaft is marked with delicate striae, which terminate at the edge of 

 the former. One side of the end of the bone is nearly plane, the other 

 is longitudinally excavated ; some shallow grooves furrow the angle 

 with the trochlear face. The section of the shaft, three inches from the 

 end, is a wide, transverse parallelogram. This bone looks no little like 

 the distal end of a metapodial bone, but there are various reasons why 

 it is more probably femur or humerus. The form of the tibia especially 

 determines it to be the former element. 



The head and distal end of the tibia, with six inches of the shaft, are 

 preserved. The former relates with the end of the femur, resembling it 

 both in size, simplicity of contour, and details of surface. The form is 

 crescentoid, one horn being the cnemial crest, the other posterior and 

 replaced by a short truncation. The inner (convex) face is rendered 

 angular by a median tuberosity, and all round this margin shallow 

 grooves cut the solid angle at irregular distances. The articular face 

 displays the smooth area, and the shaft the delicate strife, seen in the 

 femur. The distal end is unsym metrically lenticular in section, one side 

 being more convex; the articular face is rugose, showing a fixed liga- 

 mentous articulation for the astragalus. The convex face of the shaft 

 is coaTsely striate-grooved near the extremity ; on the other side, the 

 intervening ridges are represented by exostoses or rugosities. The 

 flatter side becomes the more convex on the lower part of the shaft. 



