AND CLASSIFICATION OF THE FOSSIL REPTILIA. 
205 
the bones diverged posteriorly. Hence I conclude that the sphenoid came between 
them after the type of Ichthyosaurus, and Lizards and Birds. The palatine bone 
shows some indication of having been slightly overlapped posteriorly as well as 
along one side of the anterior margin. The former character I take to indicate 
connection with the pterygoid bone, the latter with the vomer. We are entitled 
to infer on general analogy that the vomerine bones converged anteriorly. On 
this basis I reconstruct the palate with a slight median vacuity, less open than that 
of Ichthyosaurus; but there is no evidence whether there was a similar pre¬ 
sphenoid rostrum. There was a pair of lateral vacuities external to the pterygoid 
bones. The premaxillary bones and maxillary bones are necessarily external to the 
vomera and palatines, but their transverse width depends to some extent upon the 
Fig. 1. 
Partial Restoration of the Palate of 
Protorosaurus Speneri. Of the natural size. 
Fig. 2. 
Restoration of the Upper Surface of 
the Skull of Protorosaurus Speneri. 
degree to which the vomer laps along the palatine. In the restoration this parallelism 
of the two is represented, so a,s to carry the vomer far back ; its position may have 
been more forward, and then the palatal plate of the premaxillary would have been 
narrower. The distance from the condyle of the quadrate bone to the extremity of 
the snout is 8'5 centims., that being the length from the articulation in the articular 
bone to the anterior extremity of the lower jaw, which is inferred to have extended as 
far forward as the snout. As the bones of the side of the jaw give no evidence of lateral 
constriction, the outline of the skull was an isosceles triangle or sugar-loaf contour. 
The restoration of the upper surface of the skull is constructed on the basis of the 
