Foot-prints of Birds, fyc, in the Valley of the Connecticut. 517 



the very flags on which Ornithichnites occur; and from this he infers, 

 that there were eruptions of trap, accompanied by upheaval and par- 

 tial denudation, during the deposition of the red sandstone. 



With respect to the impressions having been made by birds, Mr. 

 Lyell states, that until he examined the whole of the evidence he 

 entertained some scepticism, notwithstanding the luminous account 

 given by Prof. Hitchcock. In proof of their being the foot-prints of 

 some creature walking on mud or sand, he mentions, 1st, the fact of 

 Prof. Hitchcock's having seen 2000 impressions, all, like those he had 

 himself examined, indented in the upper surface of the layer, the 

 casts in relief being always on the lower surface ; and 2ndly, that 

 where there is a single line of impressions the marks are uniform in 

 size, and nearly uniform in distance from each other, the toes in the 

 successive steps turning alternately right and left. Such single lines, 

 Mr. Lyell says, indicate that the animal was a biped, and the trifid 

 marks resemble those which a bird leaves, there being generally a 

 deviation from a straight line in any three successive prints ; and his 

 attention having been called to indications of joints in the different 

 toes, he afterwards clearly recognised similar markings in the recent 

 steps of coots and other birds on the sands of the shores of Massa- 

 chusetts. Prof. Hitchcock has shown, that the same impression ex- 

 tends through several laminae, decreasing in distinctness in propor- 

 tion as the layer recedes from that in which it is most strongly marked, 

 or in proportion as the sediment filled up the hollows and restored 

 the surface to a level ; and Mr. Lyell states, that he has observed a 

 great number of instances of this fact. 



He also says, that he can scarcely doubt that some of the impres- 

 sions on the red sandstone of Connecticut are not referable to birds, 

 but he believes that the gigantic ones described by Prof. Hitchcock 

 are Ornithichnites. At Smith's Ferry they are so numerous that 

 a bed of shale many yards square is trodden into a most irregular 

 and jagged surface, so that there is not a trace of a distinct footstep ; 

 but on withdrawing from this area to spots where the same tracts are 

 fewer, the observer, Mr. Lyell says, is forced to admit that the effect 

 in each case has been produced by this cause. 



On examining the shores on some small islands about fifteen miles 

 south-east from Savannah, the author was struck with the number as 

 well as the clearness of the tracks of raccoons and opossums imprinted 

 in the mud during the four preceding hours, or after the tide had be- 

 gun to ebb. At one spot, where the raccoons had been attracted by 

 the oysters, the impressions were as confused as when a flock of 

 sheep has passed over a muddy road ; and in consequence of a gentle 

 breeze blowing parallel to the line of cliffs composed of quartzose 

 sand, the tracks had in many places already become half-filled with 

 blown sand, and in others were entirely obliterated ; so that if the 

 coast should subside, the consolidation of this sand would afford 

 casts analogous to those of Storeton Hill in Cheshire, yet the im- 

 pressions had been made and filled in a few hours. 



When considering the broad question whether the fossil foot-prints 

 were made by creatures walking on mud or sand after the ebbing of 



