37 
shall have occasion to notice hereafter remarkable 
tracks of these animals in the old red of Morayshire, 
in Scotland. 
The most distinct of the traces of chelonians are 
on the large slab lately obtained for me by President 
Hitchcock from Greenfield. (Vide Plate.) This in- 
teresting slab contains the traces of quadrupeds, 
various birds, and two trails of chelonians: the largest 
of these is nearly five feet long, and four inches in 
diameter. The trail is composed of a number of 
parallel elevations, comparatively superficial. 
GROUP NINTH. 
Of the ninth group, containing the marks of Anne- 
lide, Crustacea, and Zoophytes, we have various 
specimens. 
The impressions of insects do not seem as yet to 
have been distinguished on the ancient rocks. There 
is reason to believe, however, that many of the marks 
we discover in the rocky beds might have been made 
by the feet and bodies of large insects; and small 
species of the same tribes have been found imbedded 
in, and actually constituting, immense masses of ‘cal- 
careous and siliceous rocks. 
