SOME DIN 0 S A TJRI AN REMAINS. 



701 



stricted cylindroid form with plane or gently concave articular ends. 

 The presence of a large internal space now filled with clay points to 

 the persistence of an intracentral, nodal swelling of the notochord. I 

 refer these vertebral centra to the lumbar region. 



Femur. — This bone (the left) is in excellent preservation, though 

 somewhat flattened by pressure. In its straightness, and scarcely 

 observable axial twist, it closely repeats the femur in the type of 

 Omosaurus armatus. Its proximal end bears a well-marked oval 

 articular caput separated by a shallow depression from a massive 

 external trochanter lying at the same level, and not divided from 

 the shaft by the deep narrow cleft which is so marked a feature in 

 the Iguanodontidse. The distal end of the bone exhibits the common 

 condylar division ; the inner condyle is rather more prominent an- 

 teriorly, the outer condyle broader. The dorsal or extensor surface 

 is traversed longitudinally by a depression, wide and shallow in its 

 proximal part, narrower at the middle of the shaft, and deeper and 

 wider distally, where it runs out between the condyles. A low, 

 narrow, but perfectly distinct, crest-like inner trochanter is present 

 at the inner border of the bone, at the middle of the shaft. The 

 posterior intercondyloid groove is deep and wide. The length of 

 this femur is 100 centim., the breadth of the proximal end is 28 

 centim., that of the distal end 27 centim., and that of the middle of' 

 the shaft at the level of the inner trochanter 13 centim. ; the 

 diameters of the caput femoris are 12-5 centim. and 14*5 centim. 



Metapodium. — A bone which I refer to the metatarsus, from its 

 likeness to the metatarsals of Stegosaurus (all the component bones 

 of the foot of which are figured by Prof. 0. C. Marsh), is 14-5 centim. 

 long. Its shaft has a cylindroid figure flattened at one side. Its 

 middle is gently constricted, and its ends expanded. The contour 

 of the proximal end is a roughly quadrilateral figure, in which the side 

 answering to the flattened sides of the shaft is straight, the opposite 

 side being convex. The distal end is unequally subdivided into two 

 condyles, the larger of which is prolonged much further on the 

 plantar aspect than is the other. This longer condyle coincides with 

 the convex border of the shaft and similarly convex aspect of the 

 proximal end. I am disposed to refer this bone to the outer side of 

 the left foot. 



The correspondence of these remains with those of Omosaurus 

 armatus, R. Owen, is so close that I cannot hesitate to refer to this 

 genus the Dinosaur which they represent. The chief differences, the 

 less massive forms of the bones and the hollowness of the vertebral 

 centra, may only express differences of age. In these points and 

 also in the more narrow and elongated form of the prseacetabular 

 process there is a closer approach to Stegosaurus 0. C. Marsh, 

 between which and Omosaurus, the very closest affinity exists. For 

 this new sp'ecies I propose the distinctive name of Omosaurus duro- 

 brivensis, from the name of a Roman settlement near the present 

 site of Peterborough. 



Dermal Armour. — All the remains just described were associated, 

 affording a strong presumption of their having all been parts of one 



