730 SLMGIQVEES. JA ON SINMQIDIEIN TCS, 
dilia, and possibly the Thertodonta must be regarded as the 
descendants of this order. Through the Dinosaurs the Birds are 
related to the order, and through the 7heriodonta the Mammals. 
Rhynchosaurus and Hyperodapedon are two forms from the 
Triassic, Elgin Sandstones of Scotland and the Triassic beds of 
Warwickshire in England. The latter genus has also been 
described from the Maleri, Triassic, beds of the East Indies. 
They were small forms, quite similar in external appearance to 
the modern lizard, except that the incisor teeth of the jaws were 
developed as great curved processes. The roof of the mouth 
was covered with teeth, and there was a single external nostril. 
Homeosaurus and Sapheosaurus are from the Upper Jurassic of 
Germany and France, notably the Lithographic Slates of Kel- 
heim. They were very similar to the modern lizards in appear- 
ance. 
Sauranodon, from the Jurassic of Cerin in France, was similar 
to the foregoing, except that the jaws were greatly extended and 
were edentulous. 
Champsosaurus, from the Upper Cretaceous, Laramie of Wyo- 
ming, and the lowest Eocene, Puerco of New Mexico, and 
Simedosaurus, from the Eocene of France and Belgium, are very 
peculiar in that the articular faces of the vertebre are nearly flat, 
instead of being deeply concave, or even perforated, as in the 
majority of the Rhkynchocephaha. It has been suggested that the 
two forms are identical, but as the skull of Champsosaurus is not 
known it is impossible to settle the question. The skull of 
Simedosaurus was long and slender, with an anterior rostrum 
much like that of the modern Gavial of the Indian rivers. 
Sphenodon, from New Zealand, is the single living member of 
the order. It probably appeared in the Jurassic, though it is 
still unknown in the fossil state. 
The modern Lacertilia and Oplidia are the direct descend- 
ants of the Rhynchocephalia. The chief differences are the loss of 
the lower one of the temporal arches (in some cases of both) and 
the loss of the abdominal ossicles. Moreover, the deeply bicon- 
cave character of the vertebra, amounting in most cases to a 
