Ornithichnology. 827 



Being laid off from a scale, the figures above referred to, exhibit to 

 the eye the relative, although not the real size of the different spe- 

 cies. Fig. 15 is the only one drawn of the natural size. 



It is a natural enquiry, whether the facts that have been stated, 

 will enable us to refer these birds, of the new red sandstone era, to 

 any of the families of existing birds. The idea, that they belonged 

 to existing species^ can be indulged only by those unacquainted with 

 the history of organic remains. Judging from that history, the ge- 

 ologist will expect only slight resemblances to existing species. I can- 

 not, however, but believe that several of them, at least, were Grallae. 

 They correspond with this tribe of birds in two respects ; first, in 

 having but three toes ; as is the case with several genera of the ex- 

 isting waders. The great length of their step, also, proves them to 

 have been very long legged ; another characteristic of the Grallag. 

 1 have had but few opportunities for making a comparison ; but I 

 am satisfied that the step of our common birds, not belonging to 

 the Grallae, is generally shorter with the same size to the foot than 

 in the Ornithichnites. Thus, the common domestic hen, with a toe 

 three inches long, takes a step of only six or seven inches ; while 

 the step of O. diversus, of the same size, will average ten or twelve 

 inches. The domestic goose, with a middle toe four inches long, 

 takes a step of only seven or eight inches. The turkey, however, 

 with a foot four inches long, takes a step of just about the same length 

 as that variety of O. diversus shown in Fig. 6, (with a similar foot,) 

 that is, twelve inches long ; and the pea-hen, with the same length 

 of foot as the O. diversus, shewn in Fig. 7, falls but an inch or two 

 short of the fossil tracks in the length of the step ; but the turkey 

 and the peacock are birds with rather unusually long legs among the 

 Gallinse. 



I have not been able to obtain any examples of the length of the 

 step of the larger existing Grallas. And of the smaller species I 

 can mention only a few. The small snipe, whose tracks are repre- 

 sented in Fig. 11 on a small scale, and in Fig. 14 on a larger 

 scale, takes a step of only two and a half inches, with a foot an 

 inch long. And as I am informed by Dr. Richard Harlan, the step 

 of the Ardea Canadensis, with a foot three inches long, measures 

 from four to six inches. On comparing these steps with those of 

 O. minimus, whose foot is one inch, and its step four inches lono- 

 and with O. diversus, /3 platydactylus, whose foot is from two to 

 three inches long, and its step from six to eight inches, we perceive 

 thai the steps of the existing species are shorter than the fossil foot 



