Fig. 1 to 1, directed from below upwards, is a track consisting of six

large footsteps.

2 to 2, from above downwards; a track of four footprints, disposed almost in a right line, and very far apart.

3 to 3, a track of five footprints, from above downwards, of a large, heavy bird, like fig. 1.

4 to 4,

from above downwards, four footprints like fig. 2, disposed in a nearly straight track, and far apart.

5, a track of five heavy footprints, directed obliquely up

wards.

6 to 6, five footprints of a large bird, in a track from below upwards.

7, a series of five delicate footprints.

8 to 8, a track of eleven very small footprints, disposed in zigzag, and extending obliquely from the right extremity to the upper edge of the slab.

9 to 9, a track of four large and distant footprints, passing obliquely across the stone from left to right.

This description will suffice to convey a general idea of the nature of these extraordinary remains.

A few shapeless fragments of bones are the only vestiges of the skeletons of any animals, with the exception of fishes, that have been found in the strata which have furnished the slabs of Ornithichnites; but some coprolites have been discovered, which, from a chemical analysis, are supposed to have belonged to omnivorous birds. The enormous size of some of the foot-marks are calculated to excite much surprise. I have in my possession (through the kindness of Dr. Deane) imprints that prove the size of the foot in one species to have been fifteen inches in length, and ten inches in width, exclusively of the hind claw, which is two inches long. The footprints of this bird, when in a consecutive series of five or six, are from four to five feet apart, which must have been the length of the stride of the bird; the longest stride was probably made by the animal when running; the shortest, when walking at a moderate pace. These footsteps indicate proportions so far exceeding those of all known living bipeds,for the foot of the African Ostrich is but ten inches long,that geologists hesitated to adopt the opinions of the American naturalist, in the absence of any relics of the osseous structure of the supposed birds, although sanctioned by the high authority of Dr. Buckland, who, from the first, concurred in the views of Professor Hitchcock; and I candidly confess my incredulity, until a series of specimens sent to me by Dr. Deane, accompanied with a graphic description of the circumstances connected with their position in the

strata, brought conviction to my mind. Professor Hitchcock's last memoir on this subject embraces figures, and descriptions of footprints, which he considers as referable to twelve kinds of quadrupeds; viz.-four probably Saurians, two Chelonians, and six Batrachians. The bipedal imprints belong to eight species of thick-toed tridactylous birds; fourteen to narrow-toed tridactylous or tetradactylous species; two are probably of bipedal batrachians; and eight are not determinable.

I have described the bipedal imprints as those of birds, in conformity with the opinion entertained by the most eminent observers, who have carefully investigated the phenomena on the spot.

IMPRESSION OF THE SKIN OF THE TOES. - Unfortunately, the footprints very rarely exhibit any traces of the structure of the dermal integument, or skin, a character which would yield important evidence as to the reptilian or ornithic relations of the original. It may, therefore, be interesting to state that on a slab collected by Dr. Deane, and presented to me, there are two or three foot-marks with distinct impressions of the skin of the under surface of the toes; and this structure appears to resemble that of the Ostrich.1

This specimen is in my possession; the following note from Dr. Deane accompanied it :

"The slab is about two feet in diameter, and half an inch in thickness. On the upper surface there are two rows of small elegant footmarks, of the species termed by Professor Hitchcock Ornithichnites gracillimus; one row consists of five, and the other of six consecutive impressions. There is also a row of four footprints of a much larger species, the O. fulicoides. These are arranged around the circumference of the specimen, and their alternate order proves that they have been impressed by the same individual. There is a rare peculiarity displayed in these larger impressions that adds greatly to their interest; it is the markings of the papilla, and folds of the cutaneous integument, which are very distinct; and this character I have only observed in two other examples. The papillæ may be seen most distinct in the first, second, and fourth footstep; particularly in the last of the series, on the top of the slab. The three tracks embrace fifteen impressions, and exhibit the articulations of the toes perfectly. The surface of the stone is pitted by rain-drops, from a shower which must have fallen before the birds walked over the soft mud, and made the foot-prints. There are also indistinct traces of the trails of worms, and of an Annelide. On the reverse of the slab there are the casts of four consecutive impressions of Ornithichnites gracillimus; and a row of two, of dimensions intermediate between those of the preceding varieties."

But although the weight of evidence is in favour of. the ornithic character of these footsteps on the sands of Time, the idea of such a development of the highly organized class Aves, during the Triassic epoch, is so utterly at variance with what is known as to the existence of warmblooded, air-breathing vertebrata on the lands of the secondary formations, that until bones of birds are discovered in strata of the same age, we would repeat the salutary caution of an eminent paleontologist:-"Footprints alone, like those termed Ornithichnites, are insufficient to support the inference of the progression of the highly developed organization of birds of flight, by the creatures that have left them. The Rhynchosaurs, and the biped Pterodactyles, already warn us how nearly the ornithic type may be approached without the essential characters of the Saurian being lost; and by the Cheirotherian ichnolites we learn how closely an animal, in all probability a batrachian, may resemble a pedimanous mammal in the form of its footprints."

1

Notwithstanding, therefore, the presumptive proofs lately obtained of the ornithic origin of the footsteps on the Connecticut sandstones, I do not think we are warranted in concluding, in the absence of all vestiges of the skeletons of the animals, that the countries of the Triassic epoch rivalled the islands of New Zealand, in the abundance, variety, and magnitude of that highly organized class, of which no certain relics are known in formations of a much later period.

SIR C. LYELL ON ORNITHICHNITES.-I will conclude this notice of a subject involving questions of such deep interest, with the following extract from the admirable address of the late President of the Geological Society, which embodies the most recent observations and opinions of that eminent philosopher on the phenomena in question.

"When I first examined these strata of shale and sandstone near Jersey city, in company with Mr. Redfield, I saw at once from the ripple-marked surface of the slabs, from the casts of cracks, the marks of rain-drops, and the imbedded fragments of drift-wood, that these beds had been formed precisely under circumstances most favourable for the recep

1 "Brit. Assoc. Report on Fossil Reptiles," 1841, p. 203.

tion of impressions of the feet of animals, walking between high and low water. In the prolongation of the same beds in the valley of the Connecticut, there have been found, according to Professor Hitchcock, the footprints of no less than thirty-two species of bipeds and twelve of quadrupeds. They have been observed in more than twenty localities, which are scattered over an area of nearly eighty miles from north to south in the States of Massachusetts and Connecticut. After visiting several of these places, I entertained no doubt that the sand and mud were deposited on an area which was slowly subsiding all the while, so that at some points a thickness of more than 1,000 feet of superimposed strata had accumulated in very shallow water, the footprints being repeated at various intervals on the surface of the mud throughout the entire series of superimposed beds.

"When I first examined this region in 1842, Professor Hitchcock had already seen 2,000 impressions, each of them indented on the upper sides of layers of shale, while the casts of the same, standing out in relief, always protruded from the lower surface of the incumbent strata. Had they been concretions, as some geologists at first contended, they would have been occasionally found projecting from the upper sides of strata of sandstone. I was also much struck when following each single line of foot-marks, to find how uniform they were in size and how nearly equidistant from each other, whereas on turning to a larger or smaller set of impressions, the distance separating any two tracts in the same series immediately increased or diminished, there being an obvious proportion between the length of the stride. and the dimensions of the creature which walked over the mud.

"There are also a great number of examples where the trifid impressions exhibit three marks of phalangeal bones for the inner toe, four for the middle, and five for the outer one, as in the feet of living tridactylous birds, and in each continuous line of steps the three-jointed and five-jointed toes are seen to turn alternately right and left. In one slab found at Turner's Falls, on the Connecticut, by Dr. Deane, the fine matrix has retained marks of the integument or skin of the foot. This specimen is now in the museum of Dr. Mantell, and the impression was recognised by Prof. Owen as resembling the skin of an ostrich, and not that of a reptile. Such