176 



GEOLOGY. 



the aquatic reptiles seem to have been relatively the more favored, 

 and to have made the greater progress. 



The dinosaurs. These great reptiles still retained the dominant 

 place, but their pre-eminence was less marked than before. The 

 carnivorous forms (Theropoda) were less abundant and varied. Among 

 their representatives was the Lcclaps or Dryptosaurus, a leaping, kan- 

 garoo-like form with a length of 15 feet. 



Fig. 409. — Spoonbill Dinosaurs of the Cretaceous (Hadrosaurus mirabilis Leidy) as 

 interpreted by Knight. (Osborn, Copyrighted by the Am. Mus. of Nat. Hisr.) 



The most singular dinosaurian development appeared in the Cera- 

 tops family of the herbivorous branch, particularly in the genus Tri- 

 ceratops or Agathaumus (Fig. 410). These were very large quadru- 

 peds, with enormous skulls which extended backwards over the neck 

 and shoulders in a cape-like flange. Added to this was a sharp, parrot- 

 like beak, a stout horn on the nose, a pair of large pointed horns on 

 the top of the head, and a row of projections around the edge of the 

 cape. One of the larger skulls measured eight feet from the snout 

 to edge of the cape. This excessive provision -for defense was not 

 unnaturally accompanied by evidences of low mentality in the form 

 of a very small brain cavity. Marsh remarks that they had the largest 



