JURA-TRIAS IN AMERICA. 



465 



with many American genera, such as Laosaurus (Fig. 747) and Camp- 

 tosaurus (Fig. 748). They were tliree-toed, digitigrade, bipedal herbi- 

 vores. 



The Stegosaurs were perhaps the most remarkable of all. They 



2 



Fig. 749. 



Fig. 749.— 1. Bones of left fore-leg of Stegosaurus ungulatus (after Marsh): s, scapula; c, coracoid; 

 h, humerus: r, radius; u, ulna; I, first digit; V, fifth digit. 2. Bones of left hind-leg of Stego- 

 saurus ungulatus: il, ilium; is, ischium; p, pubis; p', post-pubis; /, femur; t, tibia;/', fibula; 

 a, astragalus; c, calcaneum; I, first digit; V, fifth digit. One sixteenth natural size. 



Fig. 750. — Outlines representing transverse sections through brain of Stegosaurus ungulatus, and 

 sacral cavity : b, brain; s, sacral cavity. One fourth natural size (after Marsh). 



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