Four Jurassic Dinosaurs of the quadruped and biped types representing the 

 group of reptiles througli which birds probably ascended. 



Fig. 2 — Broiitosaurus excelsus from the Jurassic of Wyoming (X tso)- 

 Fig. 3 — Aiichisaurus colurus from the Triassic of Connecticut (X 2V'* 

 Fig. 4 — Ceratosaurus nasicovnis ixom the Jurassic of Colorado (X ^V)- 

 Fig. 5 — IguanodoH bernissarfensh from the Cretaceous of Belgium (X jq)- '^^^^ 

 avian plan of pelvis in Fig. 5 is worthy of notice. 



