1869.] HUXLEY—DINOSAURIA AND BIRDS. 23 
x. p. 204, tab. 249. fies. 34, 5. This author studied the distal ex- 
tremity of a tibia, with applied fibular condyle, from Honfleur, which 
he was not able to assign to any known species or genus, but 
which he, with his usual sagacity, included in the chapter devoted to 
Megalosaurus. He however regarded the face of the tibia receiving 
the condyle-bearing bone as the inner instead of the anterior, 
stating that the tibia is laterally instead of antero-posteriorly 
compressed ; so anomalous is this structure among Vertebrates. He 
regarded the bone as the astragalus, and did not perceive any con- 
nexion between its ascending apophysis and a fibula, partly because 
a fibula with distinct distal articulations was received with the same 
bones. 
“‘ The fibular condyle possesses an articular facet on its exterior 
extremity (anterior, Cuvier), probably adapted to a corresponding 
face of a caleaneum. Its plane is transverse, and does not cover 
the whole extremity, the anterior margin and a knob on the ante- 
ro-superior part of the extremity projecting beyond it. Exterior to 
the middle of the upper margin of this piece, and at the internal 
base of the ascending apophysis, it is perforate, as is the cavity 
above the condyles of the humerus in the higher apes, and may 
have received a similar coronoid process of an astragalus. 
“« As compared with the species examined by Cuvier, this fibular 
condyle has a less elevated form; in Cuvier’s specimen the ascend- 
ing apophysis was flatter, broader, and directed towards the calca- 
neal facet instead of from it; it lacked the submedian perforation. 
Its tibial face appears to have been rounded, not angulate. The 
tibia presented an ascending ridge to the face by which the ascend- 
ing apophysis was applied; inthe Lelaps aquilunguis there is no 
ridge, the apophysis reposing in a slight concavity. This apophysis, 
like the slender portion of the fibula, is composed of dense bone . . 
“The direction of the condyle indicates the articulation of the 
tarsal elements to have been at a considerable angle with the shank 
of the leg, and that the animal was entirely plantigrade and was 
unable to extend the foot in line with the lower leg. The animal’s 
weight was, no doubt, shared by another tarsal bone, besides the 
astragalus, owing to the anterior position of the former. 
“In most known Dinosauria the relations of the tibia and fibula 
are similar to those in the modern Lacertilia. It would appear, then, 
that the class existed under two ordinal modifications: the first, 
including Scelidosawrus (Ow.), Hyleosawrus (Mant.), Iguanodon 
(Mant.), and Hadrosaurus (Leidy), may be called the Orrmopopa ; 
the second, including Lelaps (Cope), and probably Megalosawrus 
(Buckl.), may be termed the Gonropopa.”* 
Prof. Cope’s description leaves no doubt that Lelaps had the 
tibia and the anomalous bone which articulates with it, distally 
fashioned in the same way as in Megalosawrus, the Honfleur reptile, 
and Potkiloplewron; but it will become clear by and by that the 
. ee nes of the Academy of Natural Sciences of Philadelphia, Noy. 
