236 AN ATTEMPT TO DESCRIBE THE ANIMALS THAT MADE 



of the third, 1.6 inch; of the outer, 1.1 inch; of the heel, 1.4 

 inch. Width of the heel, 0.3 to 0.5 inch. Length of the foot, 

 3 inches ; of the step, 7.7 inches. Distance between the tips of 

 the lateral toes, 1.6 to 1.8 inch; between the inner and second, 

 0.7 inch ; between the second and third, 0.9 inch ; between the 

 third and fourth, 1.2 inch. Axis of the foot nearly coincident 

 with the line of direction. Toes nearly straight. 



Fore foot. — Tetradactylous, leptodactylous, imperfectly planti- 

 grade. Divarication of the lateral toes, 100°; of the inner and 

 second, 30°; of the second and third, 35°; of the third and fourth, 

 35°. Length of the inner toe, 0.25 inch ; of the second, 0.4 inch ; 

 of the third, 0.9 inch ; of the fourth, 0.7 inch ; of the heel, 0.5 

 inch. Width of the heel, 0.8 inch (length, literally). Distance 

 between the tips of the lateral toes, 1 .2 inch ; between the first and 

 second, 0.3 inch; between the second and third, 0.7 inch; between 

 the third and fourth, 0.6 inch. Axis of the foot nearly coincident 

 with the line of direction. Toes somewhat curved inward. Dis- 

 tance between the tracks (that is, between the tip of the middle 

 toe behind and the heel of the fore foot), to 1 inch. 



Locality. — Horse Race, Gill ; on gray micaceous sandstone. 



Remarks. — The specimen from which the above description 

 was taken is the same as that from which I drew up my description 

 of the Sauroidichnites palmatus of the Massachusetts Geological 

 Report. I then regarded the animal as a biped, though suspecting 

 it might turn out to be a quadruped. That conjecture has been 

 verified in a rather singular manner. Very recently, as the speci- 

 men would not split well, I attempted to grind down its upper sur- 

 face upon a grindstone. This brought to light a part of two small- 

 er and similar tracks, a little in advance of the larger ones ; which 

 I conceive to settle the question as to their quadrupedal origin. It 



