236 Miscellaneous. 



the origin of the bird-tracks of Prof. Hitchcock was assigned, beg 

 leave to present the following brief report : 



It may be well previously to state, that the object of the meeting 

 in appointing this committee was founded solely upon the desire to 

 produce, if possible, unanimity of opinion, there being a few of the 

 members who dissented from the views published by Prof. Hitch- 

 cock. In our country, the subject, as it undoubtedly ought, had at- 

 tracted considerable attention. It had been very favourably received 

 and republished in Europe, and from its great importance to Palaeo- 

 zoic geology, an attempt should be made to settle the question ; for 

 were the views of our highly respected member correct, we were 

 made acquainted with the earliest period in which biped animals ex- 

 isted whose foot-marks were analogous to, if not identical with, those 

 of the tread of birds. On the contrary, if wrong, we were presented 

 with another class of facts, which show that certain appearances, sup- 

 posed to belong solely to animal life, were held and presented by the 

 vegetable kingdom likewise. 



We shall now state, in a few words, what we suppose are the ge- 

 neral facts upon which Prof. Hitchcock's views were founded, and 

 then the facts of those who assumed the opposite opinion. 



The first and most obvious impression upon the mind, on looking 

 at the indentations or marks, is their thin tripartite form, resembling 

 the tread or foot-mark of those kinds of birds which show three toes, 

 the fourth one being rudimental, and are referable to no other known 

 kind of animal. The tracks or foot-marks in several localities are 

 arranged in a determinate order, like those of a bird or fowl moving 

 in a straight line, the toes or marks in all such cases being alternate ; 

 that is, if the right foot be presented on the rock, the left would next 

 follow, and thus right and left in regular succession, sometimes with 

 many repetitions. In other instances the foot-marks presented no de- 

 terminate direction or order, as might naturally be supposed of a bird 

 or any other animal having no particular place or object in view. 



In all cases where a succession of tracks was observed, there was 

 an uniform correspondence as to size, and considerable regularity as 

 to distance between the tracks. Whatever deviations were observed, 

 they were not greater than might be supposed to take place in ani- 

 mals possessed of voluntary motion. 



On some surfaces, not unfrequently one or more different kinds of 

 track were exposed, belonging, as was reasonably conjectured, to dif- 

 ferent species and genera of ornithichnites. 



That the slaty material of the rock showed that the impressing 

 body possessed force or weight, for frequently the thin layers or la- 

 minae were bent downwards for an inch or more, and that the mud 

 of which the slate was formed was of a highly adhesive or tenacious 

 character. 



In all cases the foot-mark, or part impressed, was the fixed part 

 of the rock ; the part removed when the lower side was turned up- 

 wards showed the cast, or what corresponded with the toes or foot. 

 That no trace of any organic matter could be perceived occupying the 

 cavity or mould, the cast or part in relief being in all respects like 

 the material of the rock of which it formed a part. 



