518 SI QWOVUES NOME SL (CIOVEIN TOS, 
last step of the amphibian line or the first of the reptilian. The 
development of reptilian forms at the beginning and throughout 
the Permian time was most remarkable; it seems as if the con- 
ditions had been preparing for a long time and with the dawn 
of the Permian disappeared the last obstruction to the growth 
of the reptiles which appeared at once in the greatest profusion. 
Not only were there great numbers of forms, but they were, 
even in the earliest time that we know them, already highly 
specialized. The group that is discussed first, the Parezasauria, 
is nearest to the amphibia in many of its characters, while in 
others it is one of the most specialized of all the vertebrates. 
The Permian time has perhaps a larger number of highly and 
curiously specialized forms than any other time. : 
In 1840 there was discovered in the Karro formation, Per- 
mian or Permo-Triassic, of South Africa, a large number of fossil 
remains that were shipped to the British Museum, and there 
described by Professor Owen as a reptile closely related to the 
dinosaurs, and named by him, Paretasaurus bainii. Later a 
nearly perfect skeleton was found and described by Professor 
Seeley, who redescribed the genus and species and placed it in 
a distinct order, the ‘Parezasauria (1863). As this animal is 
typical of the whole group it may be described somewhat in 
detail. 
Pareiasaurus was one of the largest as well as one of the most 
amphibian-like of all the reptiles. The head was covered with 
large bony plates that had practically the same arrangement as 
in the Ladyrinthodontia; the bones formed a complete roof, leav- 
ing only five openings in the skull, the orbits, nares, and the 
pineal foramen; there were traces of the sensory tracts on the 
surface of the skull, as in the largest of the Ladyvrinthodontii; the 
teeth were equal in size and distributed all around the edges of 
both jaws in an even series; there were small teeth arranged in 
rows on the palatine and the vomer bones in the roof of the 
mouth; the limbs were short and strong, with well-developed 
articular surfaces, and the feet were provided with strong claws; 
there were eighteen presacral vertebra. This is of considerable 
