Fossil Footmarks found in Westmoreland Comity, Pa, 345 



with the front ones ; all the toes have long and pointed claws ; 

 length of the foot 9 inches ] length of the step varied from 2 to 

 15 or 18 inches. 



Ornithichnites Culbertsonii, (fig. 2.)* Toes 4, and much re- 

 semble the preceding ; the hind toe, however, is longer and more 

 blunt at its extremity ; the front ones spread at an angle of 70°. 

 Length of the foot 4^ inches; length of the step uniformly 11 

 inches. The tracks were nearly in a straight line, and traceable 

 for a distance of ten or twelve feet, the last step leaving a vivid 

 imprint on the perpendicular side of the stone. This indicates 

 that the position of the rock has been changed since these birds 

 left their footprints on its plastic surface. The popular error, that 

 these are the tracks of wild turkeys, needs no discussion. 



The following species to figure 6, inclusive, may be the tracks 

 of Saurians : yet this is only a conjecture. There is certainly 

 some resemblance in these footprints to the order Digitigrada, 

 but it is very improbable that animals of this division should be 

 associated with aquatic birds, or that they should be even rep- 

 resented at this early period of our planet. They may consti- 

 tute the new genus Spheropezium. The name is from afaiga, 

 sphere, and yregta, sole of the foot. 



Fiff. 3. 



Reduced one half. 



Spheropezium leptodactylum, (fig. 3.) Toes 5, spreading like 

 an open fan, 160°; they are two inches long, and spread five 



* This species I have named after my friend Alexander Culbertson, Esq., a gen- 

 tleman of very acute and penetrating mind, who had_the kindness first to direct 

 my attention to these remarkable bird tracks. 



