OF FOSSIL FOOTMARKS. 259 



of my Report, from a specimen in my cabinet, which I have 

 refered to O. cuneatus, belongs to the O. fidicoides ; but the ex- 

 tremity of the toes has been very much effaced. 



PI. XI, f. 4 exhibits a slab of this species which was originally in 

 the cabinet of Dr. Deane. But he has kindly divided it in order 

 that one row of these tracks should be placed in my collection : 

 and I am sorry to learn from him that his portion of the slab has 

 been accidentally destroyed. On two accounts, it is one of the 

 most interesting exhibitions of tracks which I have ever seen. 

 In the first place, these tracks all exhibit the tuberous expansions, 

 as has been described, namely, two on the inner toe, three on the 

 middle, and four on the outer toe, besides that connected with 

 the claw ; and it can be seen most distinctly how the right and 

 left foot succeed each other in regular order. In the second place, 

 on the right hand side of the drawing, two rows of tracks are 

 seen almost exactly on the same line, and situated with respect 

 to each other precisely like those of some quadrupeds; even 

 when the animal appears to have somewhat changed his course ; 

 though we cannot be sure that such was the fact, because we can- 

 not see the succeeding track ; and this animal appears to have 

 stepped wider than usual. Yet the row of tracks on the other 

 side of the slab, is obviously single ; that is, made by a biped. 

 The presumption, therefore, is, rather that the same animal walked 

 twice> along the same line, or that one followed another. I have 

 pointed out an analogous case as occm-ring in Wethersfield, 

 Connecticut, in Plate 32, figure 10, of my Report. And such 

 cases should be kept in mind ; as they may lead ultimately to 

 important results. What a pity, in the present instance, that a 

 larger sm'face could not have been examined, than this slab pre- 

 sents. 



Having been permitted to examine the feet of the Cinereous 

 Coot, {Fulica Americana,) in the cabinet of the Boston Natural 

 History Society, I was much struck with the almost exact resem- 

 blance between their indented margin and the tracks of O. Lyellii 

 and fulicoides jnst described. The number of these expansions 

 on the different toes, corresponds exactly with those upon the 



