370 
ELEMENTS OF GEOLOGY. 
a band of sandstone. Icbthyodorulites, or spines of Hyhodus^ 
teeth of tishes, and foot-prints of reptiles were 
observed by tlie same geologists in these strata. 
In the Upper Trias or Keuper the remains of 
two saurians of the order Lacertilia have been 
found. The one called Hhynchosavrus occurred 
at Grinsell near Shrewsbury, and is character- Esturia minuta, 
ized by having a small bird-like skull and jaws Fmnn. 
without teeth. The other Hyperodapedon (Fig. 391) Avas 
Fig. 391. 
Hyperodapedon Gordoni. Left Palate, Maxillary. *(Show- 
iiig the two rows of palatal teeth on opposite sides of 
the jaw.) 
a. Under surface, h. Exterior right side. 
first noticed in 
1858, near Elgin, 
in strata now rec¬ 
ognized as Upper 
Triassic, and after¬ 
wards in beds of 
about the same age 
in the neighbor¬ 
hood of Warwick. 
Remains of the 
same genus have 
been found both in 
Central India and 
Southern Africa in 
believed to 
be of Triassic age. 
The " 
Hyperodape¬ 
don has been shown by Professor Huxley to be a terrestrial 
reptile having numerous palatal teeth, and closely allied to 
the living Sphenodon of IsTew Zealand. 
The recent discoveries of a living saurian in Ifew Zealand 
so closely allied to this supposed extinct division of the La¬ 
certilia seems to afibrd an illustration of a principle pointed 
out by Mr. Darwin of the survival in insulated tracts, after 
many changes in physical geography, of orders of which the 
congeners have become extinct on continents where they 
have been exposed to the severer conjpetition 
of a larger progressive fauna. 
Teeth of Labyrinthodon (Fig. 392) found in 
the Keuper in Warwickshire were examined 
microscopically by Professor Owen, and com¬ 
pared with other teeth from the German Keu¬ 
per. He found after careful investigation that 
neither of them could be referred to true 
saurians, although they had been named Mas- 
todonsaurus and Phytosaurus by Jager. It appeared that 
they were of the Batracliian order, and of gigantic di- 
Fig. 392. 
Tooth of Lahy- 
rinthodon; uaL 
size. Warwick 
sandstone. 
