454 Miscellancous. 
of the tibia; and this is exactly its position in Archwopteryx, an 
interesting point not before seen in birds. 
The metatarsal bones of Archeopteryx show, on the outer face at 
least, deep grooves between the three elements, which imply that 
the latter are distinct, or unite late together. The free metacarpal 
and separate pelvic bones would also suggest distinct metatarsals, 
although they naturally would be placed closely together, so as to 
appear connate. 
Among other points of interest in Archeopterya# may be mentioned 
the brain-cast, which shows that the brain, although comparatively 
small, was like that of a bird, and not that of a Dinosaurian reptile. 
It resembles in form the brain-cast of Laopteryx, an American 
Jurassic bird, which I have recently described. The brain in both 
these birds appears to have been of a somewhat higher grade than 
that of Hesperornis; but this may have been due to the fact that 
the latter was an aquatic form, while the Jurassic species were land 
birds. 
As the Dinosauria are now generally considered the nearest allies 
to birds, it was interesting to find in those investigated many points 
of resemblance to the latter class. Compsognathus, for example, 
shows in its extremities a striking similarity to Archwopteryx. The 
three-clawed digits of the manus correspond closely with those of 
that genus, although the bones are of different proportions. The 
hind feet also have essentially the same structure in both. The 
vertebrae, however, and the pelvic bones of Compsognathus differ 
materially from those of Archwopteryx ; and the two forms are in 
reality widely separated. While examining the Compsognathus 
skeleton, I detected in the abdominal cavity the remains of a small 
reptile which had not been previously observed. The size and 
position of this enclosed skeleton would imply that it was a foetus ; 
but it may possibly have been the young of the same species, or an 
allied form that had been swallowed. No similar instance is known 
among the Dinosaurs. 
A point of resemblance of some importance between birds and 
Dinosaurs is the clavicle. All birds have those bones; but they have 
been considered wanting in Dinosaurs. ‘Two specimens of Jguano- 
don in the British Museum, however, show that these elements of 
the pectoral arch are present in that genus. Some other Dinosauria 
possess clavicles; but in several families of this subclass, as I regard 
it, they appear to be wanting. 
The nearest approach to birds now known would seem to be in 
the very small Dinosaurs from the American Jurassic. In some of 
these the separate bones of the skeleton cannot be distinguished with 
certainty from those of Jurassic birds, if the skull is wanting ; and 
even in this part the resemblance is striking. Some of these dimi- 
nutive Dinosaurs were perhaps arboreal in habit; and the difference 
between them and the birds that lived with them may have been 
at first mainly one of feathers, as I have shown in my memoir on 
the Odontornithes, published during the past year. 
It is an interesting fact that all the Jurassic birds known, both 
