AND CLASSIFICATION OF THE FOSSIL REPTILIA. 
109 
strongly marked, soon sinks into insignificance, and. appears to be lost before the 
neural spine becomes divided. 
The liind limb .—There is no bone of the pelvis preserved. 
The femur and bones of leg lie in natural position, with the head of the femur 
towards a transverse process of a sacral vertebra. That process (Plate 14, sa ), as in 
other animals, is wedge-shaped, 11 millims. in transverse extension, and 9 millims. in 
antero-posterior extension on its external limit, as preserved. But it is imperfect, and 
may have been wider, and may not have been so much constricted where it joined the 
centrum as the present state of the fossil would indicate. These processes indicate a 
strong pelvis. Little of the strong straight femur now remains except the crushed 
impression of its outline, in which some fragments of bone still adhere (Plate 14, f). 
The length of the impression is 7 T centims. The proximal articular surface does not 
appear to have been in quite the same plane as the distal surface. The proximal end 
is P6 centirn. wide, with the head convex arid directed laterally, but with a broad 
process or trochanter 6 millims. wide, which extends a few millims. proximally beyond 
the external border of the articular surface. If this fragment of bone is correctly 
interpreted, the articulation presents a condition which is only paralleled among Birds, 
Ornithosaurs, and Dinosaurs, though the proximal trochanter is less developed in 
Dinosaurs than in this fossil. The sides of the bone approximate so that the transverse 
measurement in the middle of the shaft is 8 millims., which width is preserved without 
appreciable diminution to the distal end of the straight shaft. The distal articulation 
is rounded from above downward, and slightly thickened on the posterior condylar 
aspect, as in a Lizard, Bird, or Qrnithosaur. The bone was hollow, with a very large 
cylindrical cavity in the shaft, quite as much developed as in Wealden Ornithosaurs 
and many Birds, and with the bony tissue cpiite as dense, though Lizards make an 
approximation in both respects. 
The tibia and fibula are imperfect distally, and only 4 '7 centims. of the bones are 
preserved (Plate 14, t, f). What remains of the bony tissue shows that the bone 
was thin in the middle of the shaft, with a large medullary cavity. The proximal end 
of the tibia is truncated, with rounded margins. Its transverse width is fully 
11 millims., while the transverse measurement in the middle of the shaft is only 
about 3 millims. This proximal expansion is partly due to a general Bird-like or 
Dinosaurian massiveness of the proximal end of the bone, and partly to the develop^ 
ment of a not inconsiderable cnemial crest, which speedily subsides distally, but forms 
a ledge against which the fibula rests. The proximal end of the bone is more solid 
than in existing Lizards. Where fractured, the bone is enlarging distally. The fibula 
is a more slender bone, with a slight sigmoid curve, nearly uniform In width, being 
3 millims. wide in the proximal half, and a little narrower distally. 
The foot.— In the region between the cervical and dorsal vertebrae remains of 
an extremity of a limb are displayed. A metapodial bone is 2T centims. long; 
extremities of other bones of a like character are exposed. Extending beyond them 
