348 O. C. Marsh— Vertebrate Life in America. 
Snakes from the same region are known only from a few frag- 
mentary remains. ’ 
he Prerosauria, or flying Lizards, are among the most 
interesting Reptiles of Mesozoic time, and many of them left 
their remains in the soft sediments of our inland Cretaceous 
sea. These were veritable Dragons, having a spread of wings 
of from ten to twenty-five feet. They differed essentially from 
the smaller Pterodactyls found in the old world, in the entire 
absence of teeth, showing in this respect a resemblance to 
modern birds; and they possess other distinctive characters. 
They have therefore been placed in a new order, Pteranodontia, 
‘ from the typical genus’ Pteranodon, of which five species are 
nown. The only other genus is Nyctosaurus, represented by a 
single species. All the specimens yet found are from essen- 
tially the same horizon, in the Chalk of Kansas. The reported 
discovery of remains of this order from older formations in this 
country is without foundation. . 
the remains discoverel in deposits of this age: the herbiv- 
by far the largest land animal yet discovered; its dimensions 
being greater than was supposed possible, in an animal that 
lived and moved upon the land. It was some fifty or sixty 
feet in length, and, when erect, at least thirty feet in height. 
It doubtless fed upon the foliage of the mountain forests, 
portions of which are preserved with its remains. With T%tan- 
osaurus, the bones of smaller Dinosaurs, one (Nanosaurus) not 
larger than a Cat, as well as those of Crocodiles and Turtles, 
are not uncommon. The recent discovery of these interesting 
remains, many and various, in strata that had long been pro- 
