138 
ans, Rogers and the Appalachians, Lyell andthe Tertiaries, 
are not more household terms in the history of our science, 
than is “ Hitchcock and the New Red Sandstone” of the 
Connecticut River Valley, with its beautiful trap ranges, 
Mount Tom, Mount Holyoke, and the rest of them; and its 
Robinson Crusoe footsteps in the sand of an age so ancient 
that the silence of the dawn of an eternity seems brooding 
in it, — broken only by the weird cries of these birds, or the 
horrid croaking of batrachians huge as our pachyderms, 
among whom they fed. This ancient mystery reminds one 
of the horrid stories of the haunted house of Pottsville, 
where the inmates would be sitting at their work, the doors 
would fly open, sighings would pass along the air, footsteps 
would be seen pressed into the soft plush of the carpet, but 
not a form possessing the solidity and heaviness of life could 
be once observed. Although the majority of these vestiges 
seem to have belonged to quadrupeds, yet a few of them 
were probably the tracks of bipeds; and even if these 
bipeds shall turn out to be reptilian in their principal fea- 
tures, and to belong to some synthetic type, like that ex- 
pressed by the Solenhofen archxopteryx, the term “ bird- 
track” will continue to be used for all of a trifid form, and 
Hitchcock will remain the great expounder of the difference. 
His first account of them dates back thirty years. In 
1836 he published his first description of the footmarks of 
Birds (Ornithichnites) on the New Red Sandstone of Massa- 
chusetts, in the twenty-ninth volume of Silliman’s Journal. 
He followed it up with a description of those found in Con- 
necticut in the thirty-first volume ; a general table of fossil 
footsteps in sandstone and graywacke in the thirty-second 
_ Volume ; five new species in the first volume of the Transac- 
_ tions of the American Association ; still new species, with 
‘iptior ; of coprolites, in the forty-seventh volume of the 
