J. Deane on New Fossil Footprints. 75 
long legged, and also, in connection with the structure of the f 
they were waders. .This was unquestionably the character 
of the multitudes of birds whose tracks are found in the sandstone 
of the Connecticut valley. The step is comparatively long in 
all, and in many very much so. The foot of colossal individ- 
uals averages 14 inches in length, and the stride 48 inches in ex- 
tent, which gives the proportion of 1 to 34. But in some of the 
smaller varieties the proportion is vastly greater. Some individ- 
uals having a foot of 2 inches, and a stride of 22 inches, or 1 to 
; and the proportion is even sometimes greater than_ this. 
that the superior surfaces of the strata upon which distinct im- 
pressions occur, are incrusted with a thin glazing, differing in 
character and often in color from the principal mass. ‘This crust 
is formed of finely comminuted materials, such as is deposited from 
turbid water, in a state of comparative rest. This phenomenon may 
always be observed after summer rains, where water is accumu- 
lated in pools and gradually dissipated by evaporation and ab- 
sorption ; or where streams have suddenly overflowed their banks, 
and have again quietly resumed a former level. A thin, shining, 
adhesive deposit results, but an interval of several days of sum- 
mer heat is necessary to harden the surface sufficiently to retain 
the accurate form of an animal’s foot..I have frequently seen 
upon the same surface of rock several rows of footprints, made by 
different birds; the impressions made by some individuals were 
deep and imperfect, having been made while the substance of the 
rock was yet soft; others were quite superficial, though perfect, 
being evidently imprinted when the hardening process was car- 
