320 Ornithichnology. 



cause the layer of rock now laid bare, is either above or below that 

 on which the bird originally trod. The foot is twelve inches long, 

 and the step varies from forty two to forty five inches. The small- 

 ness of the foot may result merely from the situation of the layer 

 containing it ; in the manner that has been already explained. Yet 

 as the length of the step is also less than four feet, I conclude these 

 tracks to have been made by the young of O. ingens, or by a dif- 

 ferent species of the same genus. 



The O. ingens, has been found only at the Horse Race. Several 

 of these impressions, brought from the same place, may be seen on 

 the side walks in Deerfield. 



O. diversus. Three toed, with a hairy appendage in the rear ; 

 length of the foot, exclusive of the hairy appendage, from two to six 

 inches ; length of the step, from eight to twenty one inches. 



Under this species, I have embraced a great variety of specimens; 

 because I could not draw between them so definite a line of demar- 

 cation, as would be desirable. The two following varieties, howev- 

 er, are too distinct to be passed unnoticed ; and I have little doubt, 

 that they were produced by distinct species of birds. Indeed, I 

 am persuaded that several species must have been concerned in ma- 

 king all the foot marks, that I have grouped together under this 

 species. 



a clarus. Foot, exclusive of the hairy appendage, from four to 

 six inches long. Toes generally somewhat approximate and acu- 

 minate ; inner toe shorter than the outer one. Hairy appendage 

 very distinct, from two to three inches long ; perhaps a knobbed heel. 

 Step from eighteen to twenty five inches. Found in the south west 

 part of Montague ; also at the Horse Race, and probably also in 

 Northampton, and at South Hadley canal. The specimens from 

 Montague and Gill, are sometimes exceedingly distinct, so as to ar- 

 rest the attention of every one. Fig. 22, exhibits one from the 

 former place of the natural size. I have represented it in relief, be- 

 cause I found I could thus make the drawing more distinct. 



Fig. 17, is a sketch of several tracks of this variety, on a slab of 

 red micaceous sandstone, between three and four feet square, from 

 Montat^ue, now in my possession. The impressions are exceeding- 

 ly distinct and striking, and appear to have been made by two birds 

 walking side by side, at the distance of eighteen inches ; one of 

 them, taking steps two feet long, and the other, but eighteen inches. 

 In the right hand row, a third step just begins to appear on the mar- 



