50 



Two New Species of Fossil Footmarks. 



Genus Brontozoum, (pQovjrig, a giant, and Zuov } an animal.) 



Foot tridactylous, pachydactylous, the toes making strong tu- 

 bercle-like phalangeal impressions ; having claws, which in the 

 lateral toes proceed from the outer side, and in the middle toe 

 from the inner side ; inner toe shortest : all of them directed for- 



ward. 



phalan 



of the middle toe, three ; of the outer toe, four. The distal ex- 

 tremity of the tarso-meta tarsal bone double-headed ; yet rarely 



reaching the ground : the cushion beneath it, making an im- 



pression, which slopes upward posteriorly. Animals bipedal, 

 gregarious. 



Five species known : one of them of great size, — with a foot 

 eighteen inches long. 



Affinities. — The number and position of the toes, and of the 

 phalanges of the several toes, as well as the manner in which the 

 steps succeeded one another, ally the animals to birds. The 

 deficiency of the hind toe, and the great length of most of the 

 steps, ally them to Grallae. The great thickness of the toes, and 

 the great size of the feet in some instances, suggest a relation to 

 the Struthionidae. 



Fig. 2. 





Brontozoum parallelum. (Fig. 2, a and b.) 



Divarication of the lateral toes, 15° to 20° ; do. of the inn er 

 and middle toe, 5° to 6° ; do. of the outer and middle toe, 8° to 



