1891.] Remarks on Reptiles Called Dinosauria. 439 
3. The feet are plantigrade, with five toes on each foot. 
4. The precaudal vertebræ contain large cavities, apparently 
pneumatic. ; 
5. The neural arches are united to the centra by suture. . 
6. The sacral vertebræ do not exceed four, and each supports 
its transverse process. 
7. The chevrons have articular extremities. 
8. The pubes unite in front by ventral symphysis. 
9. The third trochanter is rudimentary or wanting. 
10. The limb bones are without medullary cavities.” 
Cetiosaurus, a member of this group, had always been con- 
sidered as one of the Crocodilia, and Owen (15) had placed it in a 
special group, Opisthoceelia. 
In this Owen was followed by Haeckel, but not by Huxley, 
who placed Cetiosaurus among the Iguanodontida. Seeley intro- 
duced the name Cetiosauria in 1874. 
Another new order of reptiles was created by Marsh (16), under 
the name Cceluria, without characters, in 1881. 
In the same year the first classification of the Dinosauria is 
given by Marsh (17). 
The Dinosaurs are considered an order, and divided in five 
suborders: Sauropoda, Stegosauria, Ornithopoda, Theropoda, 
Hallopoda, Coeluria. The diagnoses are thus given : 
Order DrnosauRIA Owen. 
“1. Suborder Sauropoda (lizard foot). Herbivorous. Feet 
plantigrade, ungulate; five digits in manus and pes. Pubes 
united in front by cartilage. No postpubis. Precaudal ver- 
tebree hollow; limb bones solid. Family, Atlantosauride; 
genera, Atlantosaurus, Apatosaurus, Brontosaurus, Diplodocus, 
and Morosaurus. 
2. Suborder Stegosauria (plated lizard). Herbivorous. Feet * 
plantigrade, ungulate; five digits in manus and pes. Pubes free 
in front. Postpubis present. Vertebre and limb bones solid. 
Family, Stegosauride ; genus, Stegosaurus. 
3- Suborder Ornithopoda (bird foot). Herbivorous. Feet 
digitigrade; four functional digits in manus and three in pes. 
