FOSSIL VERTEBRATES — REPTILIA 643 
The whole animal attained a length of about thirty feet and 
was probably about fifteen high when it stood erect. 
Hladrosaurus is from the same region as all the forms just 
described and presents the peculiar feature of a flattened snout, 
resembling the bill of a duck, or the snout of the Australian 
mammal, Ornithorhynchus. Only the skull is well known. The 
anterior ends of the jaws were edentulous, and were probably 
covered by a horny sheath; the posterior portions were filled 
with a large number of teeth that were disposed in rows, and 
were successional in arrangement so that as fast as the old teeth 
were worn out new ones, developed in the sides of the jaw, came 
in to take their places. In one specimen Cope counted six hun- 
dred and thirty teeth on each side of the upper jawand four hundred 
and six on each side of the lower jaw, making a total of two 
thousand and seventy-two. The animal was probably aquatic 
in its habits of feeding, and used the ducklike bill much as the 
bottom feeding aquatic birds do in gathering up the ooze and 
slime that contain their food. The fragments of the skeleton 
that are known indicate that the animal had the same relative 
proportions of the fore and hind limbs as Claosaurus. 
Agathaumus, most generally, but erroneously, called 77zceratops, 
Torosaurus, Claosaurus, and Hadrosaurus are all from the Upper 
Cretaceous, the Laramie, and from a very limited region in the 
northeastern portion of Converse county in Wyoming. A few 
remains of these forms have been found in near-by portions of 
Wyoming and Montana. 
L[guanodon is the European representative of the Predentata. 
It is one of the few members of the group found outside of the 
United States. It was of the bipedal type, the hind feet being 
larger than the fore feet and the whole hind limb showing the 
more robust characterso common inthe American forms. There 
were three functional toes on the hind foot and three on the fore 
foot, but there were two, the first and the fifth, on the fore foot 
that are entirely lacking on the hind foot. The first digit on the 
fore foot was modified in a most peculiar manner into a short 
and strong spurlike process that stood out at right angles to 
