Ornithichnology. ' 309 



here laid bare^ in length forty or fifty rods^ (even double this distance 

 al low water,) and several rods in width ; but it has not been exten- 

 sively wrought for economical purposes. This spot is more than 

 thirty miles south of the Horse Race ; and these are the two ex- 

 treme points of that region, in which I have discovered these Im- 

 pressions. Near the village at South Hadley canal, however, among 

 the fragments of hard gray shale, blasted out for the canal, I found 

 a single specimen ; and a fine specimen has been found in the north 

 part of South Hadley, near Mount Holyoke, on a coarse gritstone. 

 ■South Hadley lies on the east side of Connecticut river, opposite to 

 the quarry abov^e described, on the cast side of Mount Tom. 



I know of no reason why these impressions, should not occur In 

 any part of the valley of the Connecticut, where slaty sandstone, 

 similar to the varieties above described, exists ; (and this rock does 

 extend southerly from Mount Tom, sixty or seventy miles) ; but I 

 have examined the quarries in the vicinity of Hartford, and at En- 

 field Falls, as well as the flagging stones in Hartford and Springfield, 

 and have made no discoveries. -I have some reasons, however, to 

 suppose that such impressions have been found in Wethersfield ; and 

 I should think It very strange, if they are not brought to light in that 

 place, or in Middletown, or perhaps at Chatham. 



It will be seen from the preceding statement, that I have ascer- 

 tained the existence of these Impressions in five places, near the 

 banks of Connecticut river, within the distance of about thirty miles. 

 Having repeatedly visited these localities within the k\^ last months, 

 I shall now present the results of my examination : and I shall first 

 give a more general account of the impressions, and then attempt a 

 classification and specific description. 



Where the surface of the rock has been exposed for a great num- 

 ber of years, to the action. of the weather, I have never found any 

 of these foot marks. They occur only where the upper layers have 

 been removed by human, or aqueous agency. And I know of no 

 reason, why they might not be found in a hundred other places along 

 this river, were quarries to be' opened in so many places. ^ 



At the quarries above named, these impressions are exhibited on 

 the rock in place, as depressions, more or less perfect and deep, 

 riiade by an animal with two feet, and usually three toes. In a few 

 instances, a fourth or hind toe, has made an impression, not directly 

 in the rear, But Inclining somewhat Inward; and m one instance, the 

 four toes all noint forv^ard. Sometimes these ternate depressions 



