AND CLASSIFICATION OF THE FOSSIL REPTILIA. 
213 
The metacarpus has the bones more nearly equal in length than the metatarsus ; three 
are fasciculated in the middle, and the inner and outer bones are shorter and more 
spread out laterally. 
From this discussion I conclude that Protorosaurus has no predominant affinity 
with any existing order of animals. Its cranial characters appear to separate it widely 
from other ordinal groups. If the strongest resemblance of the upper surface of the 
skull is with certain Nothosaurs, the dental characters separate it. The second 
strongest resemblance is probably with certain Jurassic Ornithosaurs. The vertebral 
column as a whole has much iu common with Pterodactyles, more perhaps than with 
any other group, but the differences in the articulation of the ribs and the sacrum 
separate it. The pelvis is intermediate between that of Pterodactyles and 
Plesiosaurians or Nothosaurs. The hind-limb is in its proximal segments suggestive 
of Dinosaurs, and in its distal segments approximates to Lizards. The scapular arch 
is too imperfectly known to yield marked evidence of affinity. The fore-limb shows 
no striking differentiation. The animal is therefore of an ancient stock, and may 
have been derived from the group from which Ornithosaurs were developed. Hence 
I conclude that von Meyer was fully justified in regarding Protorosaurus as the type 
of a distinct order of Reptiles, for which the name Protorosauria may be conveniently 
used. 
Description of the Plates. 
PLATE 14. 
Figure of specimen in College of Surgeons (No. 308, natural size). 
Figs. 2-7. Cervical vertebrae : sa, transverse process of sacral vertebra ; f ’ femur ; 
ji, fibula ; t, tibia ; a, dermal armour. 
PLATE 15. 
Enlargement of skull and details of the teeth. 
Fig. 1. n, nasal; f, frontal; p, parietal; so, supra-occipital; pf, prefrontal; pm, 
premaxillary ; s, ? sclerotic armature; q, quadrate bone ; pt, pterygoid 
bone; pi, palatine bone; v, vomer ; d, dentary bone ; a, articular bone ; 
an, angular ; s.an, surangular ; sp, spleniate. 
Figs. 2, 3. Teeth in skull. 
Figs. 4, 5. Teeth on the pterygoid bone. 
Figs. 6, 7. Teeth on the vomerine bones. 
Figs. 8, 9, 10. Teeth in the lower jaw. The appearance of a fang in fig. 9 may result 
from the alveolar border rising above the base of the tooth. 
Fig. 11. Dermal armour. 
PLATE 16. 
Outline restoration of the skeleton of Protorosaurus reduced. The shoulder girdle is 
omitted. The restoration is based chiefly upon the Vienna specimen. 
