ON THE EXTINCT ANIMALS OP THE COLONIES OP GREAT BRITAIN. 255 
have afforded subjects filling seventy plates of a quarto work of 
100 pages of text. * 
I think the most extraordinary, as it was the first to be 
restored, of the old Cape reptiles was a creature attaining the 
size of a walrus, and which, like that amphibious mammal, had 
a pair of long, pointed tusks descending from the upper jaw. 
But it had no other teeth, and it combined the two-tusked 
character with a lower jaw, edentulous, like that of a tortoise, 
and a skull exemplifying crocodilian and lacertian structures. 
Many species of this type, varying in size, came successively to 
hand, and exemplified the genus called Bicynodon . Other 
two-tusked reptiles required a distinct generic section, called 
Ptychognathus. A third extensive series carried the tortoise 
likeness further by the absence of tusks, but with the same 
composite cranial structure as in the Bidentals ; and, in short, a 
series of Beptilia was brought to light which necessitated the 
formation of a new order in the class, to which was assigned the 
denomination of Anomodontia. 
Now, although no true coal has been met with in the Karoo 
strata, although present in the older Devonian series, at the 
Cape, called the Kowie Coal Beds, yet remains of a rich series of 
vegetation on the land traversed or occasionally visited by the 
Karoo reptiles have been detected. I was not surprised, there- 
fore, to receive evidences of huge herbivorous dragons, akin, 
although remotely, to our own liassic scelidosaurs and the 
Wealden iguanodons. 
The jaws of the Tapinocephali , of the Pareiosauri , and of 
the Anthodons were armed with close-set series of equal-sized 
teeth, having crowns adapted to crush and pound vegetable 
substances, and were associated with modifications of the skull 
for horizontal grinding movements of the jaws. A significant 
fact was elicited by scrutiny, and sections of parts of the back- 
bone of these Dinosauria. The bodies of the vertebrae retained 
more of the foetal structure than has been met with in any post- 
triassic herbivorous reptile. Those of Anthodon , for example, 
were bi-concave, as in fishes ; and those of Pareiosaurus and 
Tapinocephalus carried the primitive embryonal character a 
degree further. The apices of the hollow terminal cones, which 
nearly meet in the centre in Anthodon , quite meet in the other 
genera, exemplifying the persistence in those huge dragons of a 
continuous, beaded notochord. Hence the necessity of placing 
them in a distinct section of Dinosauria, called “ Tretospondylia,” 
and it may be, as our restorations become completed, that erpe- 
tologists will regard them as the types of an order distinct from 
the later forms of Dinosauria. 
* “ Description of the Fossil Reptilia of South Africa,” 4to. 2 vols. 1876. 
By Professor Owen. Published by the Trustees of the British Museum. 
