CONNECTICUT RIVER SANDSTONE. 57 



PLATE XXXVIII. 



Fig. 1. Drawings in outline of the tracks here represented were given by Dr. Deane 

 in his communication to the American Academy, in 1856. He then supposed them to 

 have been made by a Batrachian, the impressions of the anterior feet not being retained. 

 Subsequently, he judged them to have been made by a biped. 



Dr. Hitchcock thinks the impressions to be Chelonian, and has described them in the 

 Ichnology as of an animal which he calls the Exocampe ornata. 



Fig. 2. Drawings in outline of these tracks were also given by Dr. Deane, in the 

 communication above referred to. Like the last mentioned, he judged them to have been 

 made by a Batrachian. 



Dr. Hitchcock ascribes them to an animal belonging to the group of lizards, which 

 he calls the Orthodactylus linearis. 



The specimen here represented is in the cabinet of Amherst. 



PLATE XXXIX. 



The impressions shown on this Plate, Dr. Deane supposed to have been made by a 

 bipedal reptile. The stone is in the collection of Amherst. In the Ichnology of Massa- 

 chusetts, the animal is classed among the Chelonians, and has received from Dr. Hitchcock 

 the name of Exocampe arcta. 



PLATE XL. 



This Plate and the next succeeding present a series of photographic delineations of 

 the tracks of insects, or possibly of small crustaceans. Of all the impressions upon the 

 sandstone of the Connecticut Valley, perhaps none have excited more astonishment upon 

 the minds of beholders, than have those of which figures are here given. The perfect 

 portrayal of the original stones presented by these Plates is remarkable. 



Dr. Deane gave some account of these impressions in his communication to the 

 American Academy, in 1856, accompanying it with some Plates ; and Dr. Hitchcock has 

 since named, and more fully described them, in his Ichnology of Massachusetts. 



The names applied by him, as far as recognized, are here given. 



Fig. 1. Acanthichnus saltatorius; specimen in the collection of Roswell Field. 



Fig. 2. Conopsoides larvalis (?), from a specimen in the possession of Amherst 

 College. 



