1869. ] HUXLEY—TRIASSIC DINOSAURIA. 45 
The proximal end of the tibia (Pl. III. fig. 8) possesses the great 
outwardly bent cnemial crest which is characteristic of that bone in 
the Dinosauria. 
The ilia, femora, and tibic in the Bristol collection are all of one 
kind ; and the question therefore arises, do they belong to T’hecodon- 
tosaurus or to Paleosaurus? Considering that three sets of Theco- 
dontosaurian teeth have been found for only a solitary Paleeosaurian 
tooth, the probabilities would seem to be in favour of the bones be- 
longing to Thecodontosaurus. But, on the other hand, the teeth of 
Thecodontosaurus are Scelidosaurian in character; and it seems to 
be hardly likely that these teeth should have accompanied hind 
limbs which are the reverse of Scelidosaurian, and exaggerate the 
peculiarities of those of Megalosaurus, when we have, in Palewosaurus, 
a tooth so like that of Megalosaurus that it is only distinguishable 
by critical examination. With the present materials I do not think 
any decision can be safely arrived at on this question, and I shall 
speak of the bones as those of Thecodontosaurians, without prejudice 
as to the particular genus to which they may belong. 
I may observe, in conclusion, that the ilium is shorter in propor- 
tion to the femur in these Dinosauria than in any others with which 
I am acquainted, and that the cavities in the bones are so extraor- 
dinarily large and well defined that, if found alone, it would be hard 
to distinguish some of them from those of Péerosauria. 
The Thecodontosaurians, then, are Dinosauria ; but the question 
may be raised whether the conglomerate in which they are found is 
really Triassic, some geologists appearing to be inclined to think 
them of Rheetic age, while Von Meyer, as has been seen, looks upon 
them as transitional between Muschelkalk and Keuper*. It does 
not lie within my province to discuss this problem, the decision of 
which, either way, will not affect the occurrence of Dinosauria in 
the Trias ; and I therefore pass on to examine into what evidence 
there may be of the existence of Dinosaurian reptiles in the War- 
wickshire sandstones, the Triassic age of which appears to be beyond 
question. 
Many years ago certain teeth were discovered in these sandstones 
by Dr. Lloyd, and were placed by him in the hands of Professor 
Owen, who has thus described them in his ‘ Odontography,’ which 
was published between the years 1841 and 1845 :— 
“ In their compressed form, anterior and posterior serrated edges, 
sharp points, and microscopic structure, these teeth agree with those 
of the Saurian reptiles of the Bristol conglomerate. In their 
breadth, as compared with their length and thickness, they are 
intermediate between the Thecodontosaurus and the Palcosaurus 
platyodon. They are also larger and more recurved, and thus more 
nearly approach the form characteristic of the teeth of the Megalo- 
saurus. From these teeth, however, they differ in their greater 
degree of compression and in a slight contraction of the base of the 
crown.” 
* On this question I refer the reader to a forthcoming paper by my colleague 
Mr. Etheridge. 
