440 The American Naturalst. [May, 
Pubes free in front. Post pubis present. Vertebræ solid ; limb 
bones hollow. Family, Camptonotidz ; genera, Camptonotus, 
Diracodon, Laosaurus, and Nanosaurus. 
4. Suborder Theropoda (beast foot). Carnivorous. Feet 
digitigrade; digits with prehensile claws. Pubes coésified in ; 
front. Post-pubis present. Vertebræ more or less cavernous; 
limb bones hollow. Family, Allosauridæ; genera, Allosaurus, 
Creosaurus, and Labrosaurus. 
_ 5. Suborder Hallopoda (leaping foot). Carnivorous (?). Feet 
digitigrade, unguiculate; three digits in pes. Metatarsals much 
elongated; calcaneum much produced backward. Two vertebre 
in sacrum. Limb bones hollow. Family, Hallopodide ; genus, 
Hallopus. 
DINOSAURIA (?) 
6. Suborder Cceluria (hollow tail). Carnivorous (?). Family, 
Coeluride ; genus, Ccelurus.” 
The year following, 1882, the Dinosauria are placed in a sub- 
class, with five orders (18). é 
a. Sauropoda. 4. Stegosauria. 3. Ornithopoda. 4. Theropoda. 
1. Suborder Cæluria. 2, Suborder Compsognatha. 5. Hallopoda. 
The subclass Dinosauria is characterized in the following words: ; 
“ Premaxillary bones separate ; upper and lower temporal arches; 
rami of lower jaw united in front by cartilage only ; no teeth on 
palate. Neural ‘arches of _vertebrz united to centra by su 
cervical vertebrze numerous ; sacral vertebrz codssified. Cervical 
ribs united to the vertebrze by suture or anchylosis ; thoracic m 
double-headed. Pelvic bones separate from each other, and from 
sacrum; ilium prolonged in front of acetabulum ; acetabulum ; 
formed in part by pubis; ischia meet distally on median line. 
Fore and hind limbs present, the latter ambulatory and large ee 
than those in front; head of femur at right angles to condyles; | 
tibia with procnemial crest; fibula complete. First row of wo 
composed of astragalus and calcaneum only, which together ee a 
the upper portion of ankle joint.” B 
After this Cope (19) established the following system, consi d 
the Dinosaurs an order, with four suborders. : 
