FOSSIL VERTEBRATES —REPTILIA 639 
the Middle Cretaceous layers of the East Indies. The same 
vertebre have been found in the Cretaceous of England. 
A very imperfectly known form, Aepysaurus, is found in the 
Cretaceous of France. 
Imperfect remains have been described from Patagonia, 
Argyrosaurus and Titanosaurus, and from Madagascar Bothrio- 
spondylus. 
Some teeth and parts of vertebre have been discovered in 
the upper part of the Potomac formation of Maryland. 
It will be seen that the Sauropoda, as far as we know them 
now, are for the most part confined to the continent of North 
America. The few forms that are found in the other parts of 
the world indicate the wide extension of the group, but in these 
there is no indication of such a degree of specialization as was 
attained by the North American forms. This continent seems 
to have been the home of the group and the seat of their great- 
est development. 
PREDENTATA (Lewanodonta).— Brain case completely ossified ; 
a well-developed alisphenoid ; no epipterygoid (columella); pre- 
maxillaries, with a posterior outer process extending between 
the mawxillaries and the nasals, excluding the maxillaries from 
the nasal openings; jugals fixed to a special process outside of 
the alveolar process of the maxillaries ; posterior border of the 
maxillaries free, not attached to the jugal or the quadrato-jugal ; 
quadrate directed forward; the anterior end of the mandible 
furnished with a distinct predentary bone; dentary with a greatly 
developed coronoid process; sacral vertebra, with the ribs and 
the diapophyses attached, and the ribs joined to two vertebre 
(intervertebrally) ; pubis consisting of two branches, the ante- 
rior one, ectopubis (pectineal process, prepubis) extending far 
forward and joined with the one of the opposite side by suture ; 
the posterior one, the entopubis, extending far backward, and 
lying parallel to the ischium, is well developed in some forms, 
but in others rudimentary ; illum much extended in front of the 
acetabulum, and also reaching far behind. In some forms of 
this suborder the fore and hind limbs were of nearly equal size, 
