438 The American Naturalist. [May, 
6. The teeth are not anchylosed to the jaws, and may be lodged 
in distinct sockets.. They appear to be present only in the pre- 
maxille, maxillæ, and dentary portions of the mandible. 
7. The scapula is vertically elongated; the coronoid is short, 
and has a rounded and undivided margin. There is no clavicle. 
8. The crest of the ilium is prolonged both in front of and 
behind the acetabulum, and the part which roofs over the latter 
cavity forms a wide arch, the inner wall of the acetabulum having 
been formed by membrane, as in birds. 
9. The ischium and pubis are much elongated. 
10. The femur has a strong inner trochanter; and there is a 
crest on the ventral face of the outer condyle, which passes 
between the tibia and the fibula, as in birds. 
11. The tibia is shorter than the femur. The proximal end is 
produced anteriorly into a strong crest, which is bent outwardly: 
or towards the fibular side. 
12. The astragalus is like that of a bird; and the digits of the 
pes are terminated by strong and curved ungual phalanges.” 
The Dinosaurs are divided by Huxley into three families: 
I. Megalosauride ; Teratosaurus, Palzosaurus, Megalosaurus, 
Poikilopleuron, Lzlaps, and probably Euskelosaurus. 
II. Scelidosauride ; Scelidosaurus, Thecodontosaurus, Hylæo- 
saurus, Polacanthus (?), Acanthopholis. 
II. Iguanodontide ; Cetiosaurus, Iguanodon, Hypsilophodon, 
Hadrosaurus, and probably Stenopelyx. 
With 1877 begin the publications of Prof. O. C. Marsh, based 
on the extensive collections brought together by his collecto 
In 1877 a new order of reptiles is named Stegosauria, but 4 
characters are given (13). 
The year following the order Sauropoda of the Din 
established (14), to contain the very large reptiles, named by os 
Atlantosaurus, Apatosaurus, Morosaurus, and Diplodocus, i 
by Cope Camarasaurus, Amphiccelias, etc. The cha i 
this order are: r 
SAUROPODA. 
“1. The fore and hind limbs are nearly equal in size. 
2. The carpal and tarsal bones are distinct. 
A a 
osauria is 2 
= 
