10 or 12 spe- 

 cies in all. 



Prof. Hitchcock on Ichnolithology, or Fossil Footmarks. 317 



ment of the species. I include them all in the class Ichnolites, 

 or stony tracks ; and this class is subdivided into four orders, 

 founded on the number of feet in the animal that made them. 



Class Ichnolites. 



I. Order Polypodichnites, or many-footed tracks. 



1. On the forest marble near Bath in England. 



2. On the slate of Hudson River. 



II. Order Tetrapodichnites, or four footed tracks. 



1. Several species made by Chirotheria, or the Labyrinthodon 

 most probably, in Germany and England. 



2. By Saurians in England. 



3. By Tortoises in Scotland and Germany. 



4. Other Batrachiaus besides the Labyrinthodon 



in Germany. 



5. Batrachoidichnites Deweyi, at Middletown, Connecticut, 

 and Gill, Massachusetts. 



III. Order Dipodichnites, or two-footed tracks. 

 (1.) In Massachusetts, Connecticut, and New Jersey. 



a. Sub-Order Sauroidichnites, or tracks resembling those of Sau- 



rians. 



7. S. minitans. 



8. S. longipes. 



9. S. tenuissimus. 



10. S. palmatus. 



11. S. polemarchius. 



h. Sub-Order Ornithoidichnites. 

 1. Pachydactyli. 



1. O. giganteus. 3. O. expansus. 



2. O. Sillimani. 4. O. gracillimus. 



2. Pachydactylo-Ptei'odactyli. 

 1. O. Lyelli. 2. 0. fulicoides. 



Vol. xLVii, No. 2.— July-Sept. 1844. 41 



