The American Journal of Science, Ornithichnology, Hitchcock 1835

The interval, also, between the different steps, varies;sometimes several inches in the smaller impressions, and even a foot or two in the layer: just about as much, indeed, as we should

- THE

AMERICAN

ART 1.-Remarks on the Geology of the Lakes and the Valley

of the Mississippi, suggested by an excursion to the Niagara andDetroit Rivers, in July, 1833; by JOHN BANNISTER GIBSON,Chief Justice of the Supreme Court of Pennsylvania

IT is known that the principal geological formations in Pennsylvania, so far as the series extends, occur in the order of superposition inwhich the same formations are arranged in Europe We have, withtheir subordinates, granite, gneiss, mica slate, clay slate, graywackeincluding the old red sandstone, transition and mountain limestone,and the great coal formation which traverses the state from northeast to south-west, and which ought by analogy to lie immediately

on the mountain limestone, instead of the stratum of rock salt* onwhich it is proved to lie by the borings on the Ohio and its tributaries At Pittsburg, the salt is found under three distinct seams ofcoal, at an average depth of five hundred feet below the bed of theriver

In the north-western part of the state, in the western part ofNew York, in Upper Canada, Ohio, Michigan, and regions furtherwest, two superior formations occur The inferior of these, is thenew red sandstone of the English geologists, and is scarcely distinguishable by its external character from the old, which has, in thiscountry, been usually confounded with it, although admitted in Europe to be the undermost member of the carboniferous group, if not

a ferruginous graywacke The other, however, is here in place,resting on the basset edges of the coal strata which crop out along

* The statement of the author is doubtless correct as a general fact; but, it may

be added, that the salt of the West is found also above the coal, as well as below

it See Dr S P Hjldreth's memoir and sections in our last number Salt doesnot occupy, invariably, the same position in Europe, for it is found both higherand lower than the new red sandstone.-Ed

306 Notices in Natural Ilistory.

his manifesting an unusual uneasiness, and frequently thrusting hishead against and between the wire grates of his prison, as if endeavoring to effect an escape After striving and chafing againstthe wires a few minutes, the skin at the point of the head began tocleave off and turn back over the head on to the neck, in an invertedform After the animal, by pressing the part against the wires, hadsucceeded in thrusting back the skin three or four inches upon theneck, he left the wires, and throwing his body into a coil around itself, so as to embrace with the last fold the inverted skin, with a strongmuscular pressure, made at the same time a powerful effort, shot hisbody forward through the coils, which unfolded, one after another,and thus drew off the entire skin This is, in all probability, themodus operandi of the whole race, and of whom it may be trulysaid, CC they are all turncoats."

To the enquiring mind, the question might naturally suggest itself-for what reason, and by what necessity, is it, that the serpent,different from other creatures in the animal kingdom, throws off hisskin annually? To this it might be replied, the condition to whichthis animal is doomed, "Upon thy belly shalt thou go," 8c renders

it necessary to his comfortable existence, that he be furnished with acovering suitable to that condition Hence nature has provided forhim a complete coat of mail, wonderfully contrived in all its parts.Plates, greaves, scales, joints, and ligatures, are all employed in theconstruction of this protecting armor

The nicely polished scales, which ôover the under side of thebody, enable the reptile to glide along upon the ground, amonggrass; weeds, and other obstructions, with astonishing facility Thiscoat, however, is necessarily composed of a material, the nature ofwhich renders it incapable of distension.or expansion At the return of the warm season of the year, the snake awakens from historpidity, issues from his winter lodging, and having a full supply of

"

food, which that season affords, soon begins to thrive, and his

dimen-" sions increase He now finds himself too straitly laced, and takesmeasures to rid himself ofso uncomfortable a garment

I have inclosed a specimen of the cast skin of the garter snake,

by which you will perceive the inverted convexity of the crystals

of the eyes and form of the head; a fragment also of the skin of asmall adder You will notice a difference in the belly scales, as totheir proportions

Ornithichnology 307

ART XX.- Ornithiclznology.-Description of the Foot Marks ofJJird8, ( rnitliichnites) on new Bed Sandstone in Massachusetts;

by Prof EDWARD HI'rcHcocK of Amherst College

THE almost entire absence of birds from the organic remains found

in the rocks, ha been to geologists a matter of some surprise Up

to a very recent date, I am not aware that any certain examples ofthese animals in a fossil state have been discovered, except the nine

or ten specimens found by Cuvier, in the tertiary gypsum beds nearParis In the third volume- (third edition) of his Ossernens Fossiles,* he has examined all the cases of fossil birds reported by previous writers, and he regards them, nearly all, as deserving littlecredit

For this paucity of ornitholites, geologists have, indeed, assignedprobable reasons, derived from the structure and habits of birds.These render them less liable, than quadrupeds arid other animals,

to be submerged beneath the waters, so as to be preserved in aqueous deposites; and even when they chance to perish in the water,they float so long upon the surface, as to be most certainly discover

ed, and devoured by rapacious animals.t

But although these circumstances satisfactorily explain the fact,above referred to, they do not render the geologist less solicitous

to discover any relics of the feathered tribe, that may be found inthe fossiliferous rocks: and I have, therefore, been much gratified

by some unexpected disclosures of this sort, during the past summer, in the new red sandstone formation on the banks of Connecticut river, in Massachusetts

My attention was first called to the subject by Dr James Deane

of Greenfield; who sent me some cast4 of impressions, on a redmicaceous sandstone, brought from the south part of Montague, forflagging stones Through the liberality of the same gentleman, Isoon after obtained the specimens themselves, from which the castswere taken; and they are now deposited in the cabinet of AmherstCollege They consist of two slabs, about forty inches square,originally united face to face; but on separation, presenting four

* P 302 t LyelI's Geology, Vol It, p 246, first edition

* The editor of this Journal was early indebted to Dr Deane, for similar casts

of these tracks

308 Ornititichnology.

most distinct depressions on one of them, with four correspondentprojections on the other; precisely resembling the impressions of thefeet of a large bird in mud Indeed, among the hundreds who have examined these specimens, probably no one doubts that such was theirorigin Having never been injured by exposure, they are perhapsthe most perfect specimens, that I have been able to obtain Theywere dug from a quarry in the southwest part of Montague, less thanhalf a mile from Connecticut river, and elevated above that stream,not more than one hundred feet The strata there, dip easterly, notmore than five degrees; and the layer containing the impressions,was several feet below the surface Only one variety of track hasyet been discovered at that spot

Not long afterwards, Col John Wilson of Deerfled, pointed out

to me similar impressions on the flagging stones in that village.Having ascertained that these were brought from the town of Gillfrom a quarry on the bank of Connecticut river, at a place called theHorse Race, nearly three miles higher up the stream than Turner'sFalls, and eight or nine miles north of the quarry in Montague,above described, I visited the spot, and was gratified to find severaldistinct kinds of similar impressions; some of them very small, andothers almost incredibly large This quarry lies immediately upon thenorthern bank of Connecticut river; the strata dipping southerly at

an angle of 300, and passing directly under the stream, without anyintervening alluvium The rock is a 'gray micaceous sandstone, verymuch resembling, in hand specimens, some varieties of mica slate,with about the same degree of hardness and not very fissile

In passing over the side walks at Northampton, during the summer, I discovered several examples of similar impressions upon the -flagging stones These stones were obtained from a quarry in thesoutheast part of the same towv, on the east side of Mount Tom:and on resorting thither, I found numerous examples, some of themvery fine, of several kinds of tracks The strata at this spot, dip tothe east, not more than 100, and pass directly beneath Connecticutriver, by which they are washed There are three varieties of therock on which the inpressions occur at this locality: 1, a reddishshale, or'rather a fine micaceous sandstone passing into shale-thered marl, I suppose, of geologists: 2, a gray micaceous sandstone:

3, a very hard sandstone, not very fissile and quite brittle, ccioosed of clay and sand These varieties are interstratifled in a ratherirregular manner By the water, and the quarrymen, the rock is

Ornithichnolog 809here laid bare, in length forty or fifty rods, (even double this distance

at low water,) and several rods in width; but it has not been extensively wrought for economical purposes This spot is more thanthirty miles south of the Horse Race; and these are the two extreme points of that region, in which I have discovered these impressions Near the village at South Hadley canal, however, amongthe fragments of hard gray shale, blasted out for the canal, I found

a single specimen; and a fine specimen has been found in the northpart of South Hadley, near Mount Holyoke, on a coarse gritstone.South Hadley lies on the east side of Connecticut river, opposite tothe quarry above described, on the east side of Mount Tom

I know of no reason why these impressions, should not occur inany part of the valley of the Connecticut, where slaty sandstone,similar to the varieties above described, exists; (and this rock doesextend southerly from Mount Tom, sixty or seventy miles); but Ihave examined the quarries in the vicinity of Hartford, and at Enfield Falls, as well as the flagging stones in Hartford and Springfield,and have made no discoveries I have some reasons, however, tosuppose that such impressions have been found in Wethersfield; and

I should think it very strange, if they are not brought to light in thatplace, or in Middletown, or perhaps at Chatham

It will be seen from the preceding statement, that I have ascertained the existence of these impressions in five places, near thebanks of Connecticut river, within the distance of about thirty miles.Having repeatedly visited these localities within the few last months,

I shall now present the results of my examination: and I shall firstgive a more general account of the impressions, and then attempt aclassification and specific description

Where the surface of the rock has been exposed for a great number of years, to the action of the weather, I have never found any

of these foot marks They occur only where the upper layers havebeen removed by human, or aqueous agency And I know of noreason, why they might not be found in a hundred other places alongthis river, were quarries to be opened in so many places

At the quarries above named, these impressions are exhibited onthe rock in place, as depressions, more or less perfect and deep,made by an animal with two feet, and usually, three toes In a fewinstances, a fourth or hind toe, has made an impression, not directly

in the rear, but inclining somewhat inward; and in one instance, thefour toes all point forward Sometimes these ternate depressions

310 Ornitliichnology.

run into one another, as the toes approach the point of convergence:but they also sometimes stop short of that point, as if the animal hadnot sunk deep enough to allow the lice! to make an impression.Nay; at that point the stone is in some cases irregularly raised, as ifthe weight of the animal had caused the sand or mud to crowd upwards in the rear of (lie step In a few instances, also, behind thisslight elevation, there is a depression as if a knobbed heel had sunkslightly into they yielding mass

In a large number of instances, also, there is a remarkable appendage to the hind part of the impression There radiates from it inthe rear, in the larger tracks to the distance of several inches, theapparent impression of stiff hairs, or bristles The drawings appended, will convey as good an idea of this appearance, as I cangive

In all cases where there are three toes pointing forward, the middle toe is the longest; sometimes very much so In a majority ofcases, the toes gradually taper, more or less to a point: but in somemost remarkable varieties they are thick and somewhat knobbed,and terminate abruptly

In the narrow toed impressions, distinct claws are not often seen,although sometimes discoverable Iut in the thick toed varieties,they are often very obvious Much, however, in respect to this appendage, depends upon the nature of the rock If it be composed

of fine clay, the claws are usually well marked And then again,

if we chance to cleave the rock a little above, or a little below thelayer, on which the animal originally made the impression, the clawswill be very likely not to be visible; as I shall show more clearlyfarther on

" If we lift out of its bed a portion of the rock, several inches thick,

on which one of these impressions exists, and break it so that thefracture shall pass across the toes, we shall see on the edge, the successive layers of the rock bent downward, often two, three, or evenfour inches in thickness If we carefully cleave open the specimenthus raised, on one face we shall have a ternary depression, as hasbeen described; and on the other face, a correspondent figure, projecting more or less,, sometimes in high relief And these specimens

in alto retievo often give us a better idea of the structure of the footthat made the impressions, than those that are depressed For often

it is difficult to cleave a specimen so perfectly, 'that the portions of.the rock which fills the 'd'epression, shall all be got out; and in do-

Ornitliiclinology 311

ing it with a chisel afterwards, the natural face of the layers is apt to

be marred: whereas it seems to have been often the fact, that thesand and mud which filled the original track, are more firmly concreted than the rock generally, and are thus rendered scarcely fissile atall; and while the rock around the track becomes shaky, so as easily to be cleaved off, the track itself remains unaffected; and thuswith care, a fine specimen may he obtained I doubt not, but thequarrymen, had they known the nature of these relics, might havesaved in times past, many specimens of this kind: as I found fragments of this sort among the rubbish thrown out of the quarry

There is one case, in which we do not see the layers of the rockconforming to the depression produced by the track It is when thetrack was made in very fine mud, or clay, and the depression is fill

ed by the same material in a concreted form If in these circumstances, a layer of coarser materials, is superimposed, this layer oftenexhibits no traces of the impression beneath And I can easily conceive how such a change of circumstances, (perhaps a sudden rise

of the waters,) as brought on the coarser materials, should have sofilled up the depressions as to leave a level surface for the deposition

In such cases, we obtain specimens only in relief

In descending into the rock in a quarry, by splitting up the suecesive layers, we first meet with the track in rather an imperfectstate, the toes being short and blunt But by cleaving off a layer

or two, the impression becomes larger and more distinct; and sometimes claws are visible If we continue to cleave off layers beneathwhere the impression is most perfect, we may find, perhaps, sometraces of it; as for instance, the thickest or middle toe; but it ismuch sooner lost in descending, than in ascending from the layerwhere it is most perfect

I early directed my attention to the enquiry, whether these trackscould be traced in succession: that is, whether they were made by

an animal in the act of walking; and I have been agreeably surprised to find so many examplesof this sort, of the most unquestionable kind Drawings of some of the most remarkable of these, accompany this paper, (Figs 1 to 10, with Fig 15, 16, 17, 23 and 24.)But a particular description of them will come in more convenient

ly, in another place In one instance, (Fig 6.)it will be seen, that

no less than ten tracks succeed each other in such a direction, andwith so nearly equal intervals, that it is impossible to doubt that theyresulted from the continuous steps of an animal Nor does there

312 Ornithiclinology.

seeni to be any reason wily they may not be traced farther, exceptthat the layer of rock containing them, is not laid bare beyond thetenth track It is also impossible to doubt that this, and all oth

er continued tracks, were made by a biped For we search in vain

to find any corresponding or parallel row of impressions Theyare not, indeed, exactly on a right line; but the alternate tracksdeviate a little' to the right, and the remaining ones to the left,sometimes more and sometimes less, the toes being ordinarily turnedoutwards The interval, also, between the different steps, varies;sometimes several inches in the smaller impressions, and even a foot

or two in the layer: just about as much, indeed, as we should expect

in an animal moving at different paces

It has been interesting to observe, in almost every case where theimpression is distinct, how easy it is to determine whether it weremade by the right or the left foot of the animal Even in an insulated impression, this can be generally decided; and where thetracks are continuous, it is easy to see that the left and right foot alternate In the right foot, the toes, especially the middle one, areslightly curved towards the left, so as to make the exterior side ofthe bow on the right side of the track; an effect, resulting from theeffort of the animal to throw the body forward The same effortcauses the outer part of the heel in the large tracks to appear as ifthrown behind the inner part, and the reverse of all this, is true ofthe track made by the left foot (See the plate appended, exhibiting a proportional view of the tracks.)

The inclination, or dip of the rock at the different quarries, varies from 50 to 300 Yet the animals seem to have passed over

it, while in a plastic state, in every direction with equal facility Atthe Horse Race, where the dip is 300, they sometimes appear to haveascended, and sometimes to have descended, and sometimes to havepassed diagonally; yet the tracks are not at all changed by the steepness of the declivity There is no appearance as if the animal hadscrambled upwards, or slid downwards, except in one or two tracks

of great size, where the mud appears to have been rolled up a fewinches before the feet But in this case, the animal was movinghorizontally, that is, along the line of bearing of the strata; and even

on level ground, a heavy animal, moving at great speed, will produce this effect upon plastic matter So that upon the whole, theevidence is quite decisive, that these tracks were made before therock was elevated to its present situation; that is, while it was hori-

OrnitMc/inology 313zontal, or nearly so; a conclusion, to which the geologist wouldcome, from evidence independent of the impressions.

I have stated, that often the tracks can be traced in regular succession: but this is by no means always the case Sometimes different species of animals, and different individuals, have crossed oneanother's tracks so often, that all is confusion ; and the whole surface appears to have been trodden over; as we often see to be thecase, where quadrupeds, or ducks and geese resort, upon the muddyshores of a stream or pond Fig 10 exhibits a case of this kind on

a specimen of sandstone in my possession from the Horse Race

I trust i have proceeded far enough in these details, to justify me

in coming to the conclusion, that these impressions are the tracks ofbirdé, made while the incipient sandstone and shale were in a plasticstate This is the conclusion, to which the most common observercomes, at once, upon inspecting the specimens But the geologistshould be the last of all men to trust to first impressions I shall,therefore, briefly state the arguments that sustain this conclusion

1 These impressions are evidently the tracks of a biped animal.For I have not been able to find an instance, where more than a single row of impressions exists

2 They could not have been made by any other known biped,except birds On this point, I am happy to have the opinion ofmore than one distinguished zoologist

3 They correspond very well with the tracks of birds Theyhave the same ternary division of their anterior part, as the feet ofbirds Frequently, and perhaps always, the toes, like those of birds,are terminated by claws If the toes are sometimes slender andsometimes thick and blunt, so are those of birds If they are most

ly wanting in the hind toe, so are many genera of birds, especiallythe Gralke "."

I am not aware that the tracks of living birds have been much noticed; and I regret that it has not been in my power to make moreobservations of this sort, than I have done But so far as I haveexamined them, they bear a striking resemblance to the impressionsunder consideration I was particularly struck with the resemblance

at two of the quarries, that have been described; -viz a the backside of Mount Tom, and at the Horse Race The rock at theseplaces, passes under the river, whose waters have deposited a thinstratum of mud, just at the margin of the stream Here in the summer, a few small species of Gralke, particularly the sipes, resort for

314 OrnitMclinology.

food Their tracks of course, are numerous; and, were the mud to

be suddenly hardened into stone, they would scarcely be distinguish

ed from some of thetracks on the sandstone in the immediate vicinity Indeed, in one instance, the process was well nigh completed:for the water had fallen several feet and left the mud with the tracksexposed for some weeks to the sun in a dry season; o that it wasalmost as hard as stone; and had I taken a cast of the impressions,

as I might have done, I am sure it would easily have passed for thetracks in sandstone.* I merely took a sketch of a few of the impressions, which is given in Fit 14 1 could not, however, but feel,that I was witnessing a repetition of the very process by which thetracks in the stone were produced

Fig 12, is a sketch of two steps of the common goose, (AnasCanadensis) on mud The length of the foot is four inches, and ofthe step, seven inches: The space beneath the web connecting thetoes, is quite obvious on the mud; it being sunk below the generallevel, but not so deep as the toes The entire absence of.any suchappearance in the fossil tracks, makes it almost certain, that none ofthem were produced by web-footed birds The-lateral distance ofthe successive tracks in Fig 12, to the right and left of the centralline of the bird's course, is much greater than that of any of the fbssil tracks of the same size

Eig 13, exhibits the tracks of a bird, probably of the genus Tetrao, which I met with last summer; but I caught only a glimpse of

it The length of the foot, not including the hind toe, is one inchand a half, and of the step, five inches

Fig 14, has already been referred to, as exhibiting the steps of asmall species of snipe, wanting in the hind toe Its foot is only aninch long, and its step two and a half inches The same tracks areshown in Fig 11, laid off from the same scale as the fossil impressions in the first two figures, in order to exhibit their relative size inrespect to the fossil foot marks

Fig 20, shows a case of the tracks of the domestic hen (Phasianus gallus) in mud The foot; without including the hind toe, isnearly three inches long; the length of the step, inches.' This

is the ordinary distance between the tracks of this species Onlythe alternate track shows the hind toe; owing to the foot's not sinking deep enough in all cases

" Such tracks as are the subjects of this paper

Ornithic1nology 315

A few tracks of the domesticated turkey, (Meleagris gallipavo,)are shown in Fig 18, taken from impressions in snow The foot(that of a large cock turkey,) is four inches long, and the step twelveinches The hind toe points inward, so as to be nearly or a continuation backward of the outer toe

In Fig 19, a view is given of the tracks of the peahen, (Pavocristatus.) They very much resemble those of the turkey, exceptthat in those of the peahen, the impression of the hind toe appearsrather as a hole made by the end of a stick, and does not extend so

as to reach the other toes, except where the snow is deep Not including the hind toe, the length of the foot is three and a half inches; and of the step nine inches

The tracks of living birds on Figs 12, 13, 14, 19, 19 and 20, arelaid down on a much larger scale, than the fossil foot marks Butthe resemblance between them, cannot escape notice; and it ismuch more obvious in the real specimens The Gallin, however,present a more distinct impression of a heel, than 1 have seen in thefossil species, except one This is shown by the small circle near thepoint, from which the toes diverge Where the impression was veryperfect, I have observed all the little protuberances and depressions

of the bottom of the foot; but generally they are not visible, and theclaws are very rarely seen, as a distinct part of the impression

Assuming it then as established, that the tracks under consideration on stone, were those of birds, I shall proceed to give a more specific description of the several sorts, which, I think I can recognize.And since this is a department of oryctology hitherto unexplored, Isuppose I shall be justified in proposing some new terms

I include all the varieties of tracks under the term Ornithichnites;(Gpvio! and civoo') signifying stony bird tracks: and if it be convenient to speak of the subject as a distinct branch of knowledge, Ishould call it Orni¬hithnology

All the varieties of tracks which I have discovered, I include under two divisions: 1, the Fachydactyti, or thick toed: 2, the Leptodactyli, or slender toed In the former, the toes are of almostequal 'thickness through their whole extent, except that they aresomewhat tuberous; and they te'rminitte rather abruptly; not, however, without a claw In the latter, the toes are far narrower, andless thick, with an equal span: and, indeed, some of them are quitedelicate, (Ex gr Fig 15.) They taper gradually to a point, andthe claw is not often distinctly perceived Under these divisions, I

When I speak of species here, I mean species in oryctology, not

in ornithology And I doubt not, that in perhaps every instance,what I call a species in the former science, would be a genus in thelatter; that is to say, these different tracks were made by birds thatwere generically different

I am aware, that even where the whole skeletons of birds arefound, it is very difficult often to distinguish species "The difference," says Cuvier, "between two species, is.sometimes entirelyinappreciable from the skeleton Even the genera cannot always

be distinguished by osteological characters."* Is it not then presumptuous to speak of distinct species when we have nothing but amere impression of the foot? 1 presume that in following the indications derived from this single source, we cannot always avoid confounding several distinct species of birds under a single species ofornithichnites: and observation upon the striking resemblance between the tracks of several living species of birds confirms me in thisopinion But if we take into the account the size and form of thetrack, and the, distance between the successive, steps, I am confident

we can distinguish, often between those birds that were considerablyunlike one another "The places where -birds live, and the manner of their moving forward," says Duméril, "are, so to speak, indicated beforehand by the disposition of their feet Indeed, it is bythe form, the length of the feet, and the disposition of the toes, thatbirds are divided into six orders, &c."t'

-":ossernens Possiles, Tome troisieme, p 624, third edition

t Elemens des Sciences Naturel1es, Tome II, p 258, fdurth.edition

ry in Northampton, on the east side of Mount Tom, where it isabundant I found in one spot, six tracks of this species in succession, the average distance between them, being four feet This case

is represented in Fig 1, along with three other tracks of the samesize, and one of smaller size, on the same rock Indeed, I suspectfrom the numerous examples which I have seen of tracks at thedistance of four feet, that this was the ordinary step of the birdwhen walking; while it was able to lengthen it to six feet, whenmoving rapidly The examples where the steps are six feet, arenot, common

In one part of the quarry above referred to, I found the steps offour individuals of this species, all pointing in the same direction, andnearly parallel to one another; showing that four birds must havemoved along nearly together; and rendering it probable, that thisspecies was gregarious The distance between the several rows oftracks, is four or five feet An attempt is made in Fig 21, to represent the 0 giganteus of the natural size, as it extends out inbold relief, on a specimen in my possession The claws are brok

en off It is the under side of the foot, that is shown in the figure.Incredible almost as this description may seem, the specimenswhich I have obtained of this enormous species, are neverthelessmore satisfactory, perhips, than of any other species The whole

318 Orm't/zicltnoiogy

cavity made originally in the mud by the foot of the bird, has beenfilled by a siliceous concretion, differing somewhat from the surrounding rock so that the latter may be iii a good measure detached, andthe former be left standing out very naturally from the rock-pre.senting in fact a petrifaction of the entire foot Such specimens, indeed, are not common, but I have obtained a few of them; sand bymeans of gypsum casts, they may be multiplied to any extent

0 tuberosus Toes, three; length of the foot, seven to eightincles; claw distinct in some specimens; from one inch to one and ahalf long; tuberous swellings on the under side of the toes, quite distint Heel very obvious, in one or two specimens in my possession,the inner toe presents two prominences, and the middle one, three;those on the outer toe not being distiuguishable This corresponds, sofar as the inner and middle toes are concerned, with the number ofjoints in the three toed living Grallae Length of the step in thisspecies, twenty four to thirty three 'inches; occurs in Northamptoii,east side of Mount Tom; and I have seen a loose specimen of apparently the same species, obtained in the vicinity of the Horse Race,

in Gill

The most important difference between this and the last species,

C, isons ts in its smaller size It mi lit, indeed, be tbought that the 0.9 0tuberosus is but the young of the 0 giganteus But I have not noticed intermediate specimens; and besides, the middle toe of the form,er is longer in proportion to the others, than in the latter species;while the toes of the latter are a good deal more divaricate thanthose of the former

a dubius I have lately obtained from the quarry on the eastside of Mount Tom, in Northampton, a few specimens a good dealworn, which have the general form of 0 tuberosus, but they are muchsmaller, the foot being only four inches long, and the steps twelveinches Not improbably, it is a distinct species; but at present Ishall regard it as made by the young of 0 tuberosus

Fig 2, exhibits two rows of the tracks of 0 tuberosus, pointing

in opposite directions,; the impressions at one extremity interferingwith one another The length of the foot in the right hand row, aswell as of the three insulated tracks, near the upper left, hand corner

of the figure, is eight inches, and the length of the step is twenty

"

eight inches; but the foot of the left band row is scarcely seven

" inches long; and the step is twenty four inches The feet of different species, and sornetimes.of different genera of living birds, differ

Ornithichnology 319even less than these impressions; yet as the smaller ones mighthave been made by the young of the larger birds, I shall regard themonly as varieties.

Fig 5, exhibits three tracks of 0 tuberosus, on a flagging stone,directly in front of the door of the Court House in Northampton.The foot is eight inches long and the step thirty three inches; thelongest I have noticed in this species This stone was brought fromthe quarry on the east side of Mount Tom

0 ingens Three toed; length of the foot, exclusive of thehairy appendage, fifteen to sixteen inches No claws visible in anyspecimens that I have found Toes much narrower than in 0

or nine inches; so that the wholes ,length of the track is not less thantwo feet! The length of the step appears to have been about sixfeet; although I have had but few opportuties to ascertain this fact.The rock on which this species of track appears, is composed of

a fine blue mud, such as is now common in ponds and estuaries andwhere the bird trod upon it, in some cases, it seems that the mudwas crowded upwards, forming a ridge around the track in front, several inches in height Indeed, I hesitate not to say, that the impression made on the mud appears to have been almost as deep, indicating a pressure almost as great, as ifan Elephant had passed over it

I could not persuade myself', until the evidence became perfectlyirresistible, that I was examining merely the track of a bird

0 ingens, minor. Length of the foot, about twelve inches;step from forty two to forty five inches In other respects, it corresponds with 0 ingens: and although 1-was at first inclined to regard it as a distinct species, I prefer upon the whole, to put it down

as a smaller variety of 0 ingens Fig 3, exhibits a series of tracks

of this variety, copied from the face of the rock in the quarry at theHorse Race The hairy appendage is scarcely yisible on the rock,and is therefore, omitted in the figure It is Wanting, probably be-

69.0 Ornithichnology.

cause the layer of rock now laid bare, is either above or below that

on which the bird originally trod Tle foot is twelve inches long,and the Ste varies from forty two o forty five inches The smallness of the foot may result merely from the situation of the layercontaining it; in the manner that has been already explained Yet

as the length of the step is also less than fbur feet, I conclude thesetracks to have been made by the young of 0 ingens, or by'a dif

-The 0 ingen, has been found only at the Horse Race Several

of these impressions, brought from the same place, may bQ seen onthe side walks in Deerfield

0 diversus Three toed, with a hairy.appendag in the rear;length of the foot, exclusive of the hairy appendage, from two to sixinches; length of the step, from eight to twenty one inches

" Under this species, I have embraced a great variety of speciniens;because 1 could not draw between them so definite a line of demacation, as would be desirable The two following varieties, howev

er, are too distinct to be passed unnoticed; and I have little doubt,that they were produced by distinct species of birds Indeed, I

am persvaded that several species must have been concerned in making all the foot marks, that I have grouped together under this.species

clarus Foot, exclusive of the hairy appendage, -from four tosix inches long Toes generally somewhat approximate and acuminate; inner toe shorter than the outer one Hairy appendagevery distinct, from two to three inches long; perhaps a knobbed heel.Step from eighteen to twenty five inches Found in the south westpart of Montague; also at the Horse Race, and probably also inNorthampton, and at South Hadley canal The specimens fromMontague and Gill, are sometimes exceedingly distinct, so as to arrest the attention of every one Fig 22, exhibits one from theformer place of the natural size I have represented it in relief, because I found I could thus make the, drawing more distinct

Fig 17, is a sketch of several tracks of this variety, on a slab ofred micaceous sandstone, between three and four feet square, fromMontague, now in my possession The impressions are exceeding

ly distinct and striking, and appear to have been made by two birdswalking side by side, at the distance of eighteen inches ;.one ofthem, taking steps two feet long, and the 'other, but eighteen inchs 1n the right hand row, a third step just begins to appear on the mar-:

Fig 23, represents a similar specimen from the same place, and

of the same species The tracks are depressions, and most of themvery distinct There are at least,- three pairs of tracks connected

by dotted lines; that is, they are the steps of birds moving in different directions The length of the step, varies from twelve to fourteen inches Six of the tracks are insulated; that is, not connectedwith others upon the specimen The length of the foot in all thetracks, except n, is four inches; that of n, si inches The rock isfine gray niicaceous sandstone

Fig 24, shews another similar group of the same species and size

as in the last figure; n being six inches long, and the other tracksfour inches Three tracks on the lower part of the figure, and twoalong the central part, are obviously the steps of birds moving indifferent directions; the shorter steps being twelve inches, and thelonger one eighteen inches Four of the tracks, from the Horse Racequarry, on gray micaceous sandstone, are insulated

/3 platydactylus Middle toe from two to three inches long,swelling out towards the extremity in an unusual manner Hairyappendage behind very large and distinct Length of the step six

to eight inches At the Horse Race; rather common The fivesmall tracks crossing Fig 6 diagonally, belong to this variety; asixth being wanting to complete the series It differs from the variety ciarus, chiefly in the swelling of the middle toe, and in itsdiminutive size

Since the radiating lines behind the foot in 0 ingens and 0 diverstzs, are much fainter than the furrows made by the toes, we

322 Ornitliiclznology.

might expect, that by the deposition of new matter, when the rockwas forming, these lines would sooner be obliterated And such Ifind to be the fact; for I have sometimes taken a specimen, which,although quite distinct, exhibited no traces of a hairy appendage,and by carefully cleaving off successive layers of the rock, havecome at length to a layer that exhibited It Hence, I have leaned

to refer a specimen to 0 diversus, which was destitute of a hairyappendage, if in other respects it corresponded to that species Sothat, for the most part, the examples of continued tracks of that species given in the drawings, are represented as destitute of this scopiform appearance; because, in fact, they do not exhibit it on the rock.Fig 4 was sketched from a flagging stone, brought from he eastside of Mount Tom, and lying on the side' walk in front of the northdoor of the first parish church in Northampton The tracks, although a good deal worn, are yt remarkably well characterized.The right and left feet are very distinct; and the toes have almostexactly the same divergence in each track The foot is six incheslong, and the toes are much nearer to equality, as to length, than in

0 divers-us, a clarus; so that I have been almost disposed to regard these tracks as a distinct species But I supposed it most safe

to refer them to 0 diversus The length of the step is twenty oneinches

Fig 6 has been already referred to The toes of the two principal rows of tracks are shorter and more divaricate than is usual in

" 0 divèrsu,s, a clarus; and no marks of a hairy appendage are present, yet I rank them under that species The length of the foot isfour inches, and- the average length of the step twelve inches, varying from that not more than two or three inches On the left is thecommencement of another similar row of tracks, of the same species, and one insulated track I found this example in the quarry

at the Horse Race; and by enlarging the sketch, 1 might havebrought into view many other tracks But hone of them wouldhave exhibited so many steps in succession, as are shown in the pres-

"ent drawing

" Fig 7 was sketched from a specimen about three feet long, in the.possession of Dr Dwight of South Hadley He obtained it, twenty-years ago, from a farmer in the north part of that town, who had

" used it as a step stone, before the door of his house, and it was found

an the vicinity It is a coarse gritstone, much coarser than any otherrock on-which I have found these impressions The foot is betweenthree and four inches long, and has no hairy appendage Length

Ornitliichnology 323

of the step ten inches The tracks exist on this stone in relief, andare very distinct Dr Dwight informs me, that one has been broken-off; and this is supplied in the figure by dotted lines

The roe from which Fig 8 was taken, is a gray micaceous sandstone, or rather shale, brought from the Horse Race, and now forming a flagging stone, in the village of Deerfield The foot is aboutfour inches long, and the toes are a good deal divaricate, and thereappears no scopiform appendage behind The average length ofthe step is twelve inches The third track is nearly obliterated, and

it appears that the bird moved in a somewhat curvilinear direction

It will probably be suggested, that 0 diversus, with all its ties, was made by the young of the species that produced 0 ingens.And I confess, that it is not easy to point out any other distinctionthan in size But my spcimens of 0 ingens are few, and muchmore imperfect than those of 0 diversus; so that it is only in theirgeneral features that I can compare the two species; and I suspect,that better specimens would bring to light other differences For Ican hardly believe that the young of a bird, with a foot sixteen inch

varie-es long, would accompany their mother, in search of food, along themargins of estuaries, while their feet were only two inches long, if, indQed, they could ever have been so short as this; and I hope to show,

in another place, that all these tracks must have been made by birds,thus wading along the shores of estuaries or lakes Besides, the 0.diversus is fifty times more common than the 0 ingens; and can wesuppose, that in such circumstances, such a great disproportion wouldexist between the old and the young birds? Is it so with living species? I suspect it is not, although I confess myself but little acquainted with the facts in the case

0 tetradactylus Length of the foot, exclusive of the hind toe,from two and a half to three and a half inches Toes divaricate;more slender than in 0 diversus ; the hind one turned inward, so

as to be nearly in the line of the outer toe, prolonged backward Aspace, however, usually remains, between the heel and the hind toe,

as if its insertion were higher on the leg than the other toes, and itsdirection obliquely downwards Length of the step, ten to twelveinches (?) Hairy appendage wanting At the Horse Race Probably several kinds of birds are embraced under this description, forthe size of the tracks, and especially the direction of the hind toe,vary considerably Indeed, in existing birds, these differences aresometimes the only marks, exhibited by their tracks, between dif-ferent species and genera In the tracks of the domestic hen,