﻿212 ILLUSTRATIONS OF FOSSIL FOOTPRINTS 



Plate I. 



This is a miniature drawing of one of the finest specimens of fossil footprints ever 

 obtained. I discovered it several years since at Turner's Falls ; and it is now in the 

 British Museum. It is about 8x6 feet in dimensions, and the drawing is reduced to one 

 twelfth linear measure. It displays upon its surface seventy-five footprints, arranged in 

 determinate lines. There are five rows traversing the plate from side to side, consisting 

 of five and six tracks each. An impression from one of these rows is represented by 

 Fig. 2, Plate IV. There is a row of fifteen impressions of a much smaller bird running 

 upward through the left side of the plate, and a pair of them are drawn upon Plate 

 III. Fig. 3. Another row of this variety runs across the bottom of the plate from right to 

 left ; another runs downward upon the right side ; but these are imperfect, being im- 

 pressed when the stratum was too soft to retain distinctly the forms : a fourth line crosses 

 from left to right upon the upper portion of the plate. The remaining lines are impress- 

 ed by a bird whose foot is drawn upon Plate IV. Fig. 1. One line of four imprints 

 runs upward through the centre of the plate ; one line of four imprints passes over the 

 central fragment from right to left ; just below is a line of two impressions passing in the 

 same direction ; and near the bottom of the plate is another row of three impressions, 

 also passing from right to left. These several lines embrace all the footprints, and it is 

 singular that two or more footprints nowhere fall upon the same place. 



This and the next plate are given for the double purpose of representing the serial 

 order in which the impressions to be described are arranged, and to convey a general 

 idea of the manner in which these remarkable slabs were traversed by the ancient birds. 

 No other specimens have ever been found of equal perfection and richness. 



Plate II. 



This is also a miniature drawing of a specimen of ornithic footprints belonging to the 

 cabinet of Mr. D. Marsh, by whom it was discovered in 1 848. It is accurately reduced 

 to one twelfth linear measure ; the slab is, therefore, about 10X6 in dimensions, and 

 contains upon its beautiful, smooth, unbroken surface more than sixty perfect impressions. 

 It is nearly impossible to give, by a figure or description, an adequate idea of its perfec- 

 tion. The configuration of the several footprints appears to be identical ; the only appar- 

 ent difference is that of size. In this respect it is singular ; for where great numbers 

 occur upon the same stratum, as in Plate I., the aggregate usually comprises several dis- 

 tinct species. The probability therefore is, that this elegant group was impressed by 

 both young and adult individuals of the same species. The larger imprints measure ten 



