214 Miscellanies. 
low-water mark. The waters of the ancient sea must have been sub- 
ject to great fluctuations of level, which seem due to floods rather than 
tides, for it is difficult to comprehend how the shore or beach could be 
submerged and dried in the space of a few hours sufficiently to retain 
footprints. The appearance of these water marks resembles the results 
produced by still, placid water acting upon muddy margins by the gen- 
tlest ripples. 
To convey a substantial idea of the manner in which these slabs are 
traversed by footprints, I subjoin a miniature sketch of one of them, 
which is about six by three feet in superficial dimensions. It contains 
eight rows of bird’ tracks, averaging seven imprints each, generally 
advancing in pretty direct lines, some parallel to the water’s margin, 
others passing directly into or out of the shallow water. The quadru- 
peds walked in lines parallel with the water levels. Although these 
various rows of imprints were made by different individuals, yet they 
appear to be kindred species and to have been impressed nearly at the 
same time; yet some were made when the clay was quite soft, and 
others when quite hard.* 
Another of the slabs conforms to the preceding, and contains all its 
impressions in relief. Upon its upper face are four species of ornith- 
ichnites, in rows of five and six each, unsurpassed for beauty. It has 
one impression of the leaping Batrachian, a small individual to which I 
have already alluded. 
An indescribable interest is imparted by opening the long-sealed 
volume that contains the record of these extinct animals. The slabs 
were uncovered and raised under my supervision, and page after page 
with living inscriptions revealed living truths. There were the charac- 
ters, fresh as upon the morning when they were impressed, reminding 
the spectator of the brevity of human antiquity, and of the perishable 
tenure of human works. On that morning, how long ago none can tell 
vor will ever know, gentle showers watered the earth, an ocean was un- 
ruffled, and upon its boundaries primeval beings enjoyed their existence 
and inscribed their strange eventful history. 
* Explanation —1 to 1, and 2to 2, footprints of Batrachians. The formeris aseries 
of 12 pairs of impressions arranged in a direct line, deeply impressed. The latter 
were subsequently impressed by a smaller individual. The difference in size be- 
tween the anterior and posterior feet is great. For a particular description of this 
species, see this Journal, Vol. xtviu, p. 158, figs. 1 and 3. 1 to 1 is of the size of 
fig. 3. 3 to 3, and 4 to 4, are deep imprints of birds whose feet were four or five 
inches long. The remaining lines vary in size and stride, but have a strong iden- 
tity. These slabs are somewhat divided by joints, which unite accurately. 
