The course of creation

by John Anderson

Again, however, the ashes of the dead have been disturbed, the history has been recast, and the old genealogy attempted to be restored. Sir P. G. Egerton, in a paper read before the Geological Society of London, on the 19th April, 1848, and a copy of which he did me the honor to transmit, has examined very minutely every organ and portion of the animal as delineated in the “Monograph,” and is satisfied that it is, indeed, still to be regarded as a genuine pterichthys. However, Sir Philip very cautiously adds,—“Having never seen a specimen of pamphractus, I should not be justified in expressing any positive opinion respecting this genus, but I cannot help thinking that it is founded on a specimen, showing the true dorsal arrangement of the lorication of the Pterichthys.” Accordingly, Mr. Miller, who supplies a considerable portion of the paper in question, affirms, with abundant confidence, that he has been able to penetrate the mystery of the error. “I have succeeded,” he says, “in tracing to its origin the Pamphractus of Agassiz. The specimens which he figures could never have furnished the materials of his restoration—These materials he evidently derived from the print of a Pterichthys of the upper Old Red (showing the dorsal superficies of the creature), given by the Rev. Dr. Anderson of Newburgh, in his Essay on the Geology of Fifeshire (‘Quarterly Journal of Agriculture,’ Vol. XI, 1840), as that of a fossil beetle.” Now, with all submission, this hypothesis is wide of the fact. While Mr. Miller was inspecting, at Aberdeen, “the bona fide ichthyolite itself,” and which, as we shall immediately see, was not a Pterichthys, Agassiz had both the print and the real specimens lying before him. The impressions on the slab are eleven in number, three of the “broad” and eight of the “narrow” species; and, comparing the one with the other, the print with the fossil, he records, “They have been figured very fairly by Mr. Anderson, in his interesting Memoir on the Geology of Fifeshire.” “But,” adds Mr. Miller, “I have ascertained, by the examination of the greater number of specimens of this species yet found, in the general outline of the carapace, which was longer in proportion to its breadth than in the print, and not defined by such regular curves.” ... The print is a perfect transcript of the fossil, as if taken in a mold,—curves, projections, and tubercles all duly and “fairly” preserved, as in the original; and, with all the materials, and so many actual impressions before him, Agassiz hesitated not to change his views, and to feel assured that it was really a Pamphractus, not a Pterichthys, that he was examining. Farther, we have only to add, that in the Essay in the Quarterly Journal of Agriculture, it is not true that the print of a Pterichthys is there “given as that of a fossil beetle;” the higher patronymic had, ere the publication of the prize essay, been withdrawn; and the author, along with all others, states, he was waiting the judgment of the highest and most competent authority from the blue lake of Neufchâtel.

And thither also, it would now appear, that other inquiries had been transmitted respecting the organisms of Dura Den, to be famed by modern, as it had already been by ancient, genealogical claims. We suspect, at least, it is of “the bona fide ichthyolite itself” that M. Agassiz, in the “Monograph,” speaks in the following extract:—“Dr. Fleming m’a communiqué le dessin d’une pétrifaction recueillie par lui à Dura Den, qui resemble beaucoup, quant à la forme du Pamphractus hydrophilus. La tête est courte, arrondie, large, presque en forme de croissant, le corps est allongé, formant avec la tête un ovale qui se termine en pointe en arrière. Les pectorales sont grêles, courbées et aussi longues que le corps. L’articulation de la tête avec le corps est très-nettement marquée, d’une manière qu’a la forme de la carapace près, qui est beaucoup plus pointue, on croirait voir un Pamphractus. Mais ce qui distingue surtout ce fossile (à en juger du moins d’après le dessin qui n’est, à vrai dire, qu’une esquisse) c’est qu’il n’y a pas de plaques separées, et que toute la surface de sa carapace ne montre qu’une granulation uniforme et continue, si toutefois la délinéation des plaques n’a pas été omise par le dessinateur. Nous aurions donc dans ce fossile un genre nouveau de cephalaspide, caractérisé par la forme de sa tête et par sa carapace uniforme. Quoi qu’il en soit, j’attends de plus amples informations sur ce sujet, avant de préciser davantage les caractères de ce type, et je me borne à reproduire les contours de ce dessin, Tab. 31, fig. 6, afin de fixer d’une manière plus particulière l’attention sur ce fossile.”

Now, making every allowance for the imperfection of the sketch of Dr. Fleming, (qu’une esquisse), and which had not the aggravation of being a “print,” only see how many marvels have been successively evolved out of “the bona fide ichthyolite itself:”—it is not a Pamphractus, though very much resembling it in form—it is not a Pterichthys, of which alliance there is not a hint even dropped by Agassiz, though its character as a Pterichthys Mr. Miller “found very obvious;” but “we have in that fossil a new kind (genre) of cephalaspis, characterized by the form of its head, and by its uniform carapace,” all which characters have been overlooked in “the pleasure of examining the bona fide ichthyolite itself—one of the specimens of Dura Den, and apparently one of the more entire.” Has this creature undergone a still further metamorphosis, numerous as those of the Pterichthys itself? Or what specimen is it which now rejoices in the appellation of Homothorax Flemingii, also again challenged or suspected at least by Sir P. Egerton, not to be its true designation! But, quocunque nomine gaudeat, the cabinet of science is enriched by the addition of a new and remarkable fossil fish.

Repeatedly, since the notice in Mr. Miller’s work of the Dura Den fossil, and his fanciful commentary on the truth and accuracy of the plate in the “Geology of Fifeshire,” have I examined, compared, and recompared the design and the original, and never have I been able to detect the slightest disagreement, even in the minutest feature. Others, and parties innumerable have examined them freely in my presence, have pronounced as to the fairness of the representation. There are five figures in all upon the plate of the Dura Den fossils; they were all, fossils and figures, under the ocular inspection of M. Agassiz; one of these, Holoptychius Andersoni, he has figured in the “Monograph;” the representations are identical, and all are declared to be “figured very fairly.” True, the pamphractus had not been able to preserve the tail, nor any trace even of that member. Agassiz did not think himself justified in supplying the deficiency. I added none either, “carefully sinking” the nonentity. But Mr. Miller had a point to establish: the fossil must be one and the same with the bona fide ichthyolite itself, which appears to have retained the caudal appendage. It will not certainly account for the obliteration of this organ in all the specimens of Dura Den, that, in common with Pterichthys and Coccosteus, the Pamphractus was not possessed of the heterocercal structure, so characteristic of the fishes of the period. But yet it is not there. Then, “the tubercles seen in profile,” are exaggerated: Agassiz thought fit, upon examination, to retain the exaggeration, as Nature, he perceived, had designed. And now, Mr. Miller finds it proper to communicate to Sir P. Egerton, that after examining the specimens (presented by me) in the Museum of the Highland and Agricultural Society in Edinburgh, “one of the most striking specific distinctions of the creature consists in the length and bulk of the arms, and the comparatively great prominence of those angular projections by which they are studded on the edges—projections which seem to be but exaggerations of those confluent lines of tubercles by which the arms of all the other species are fringed.” So, Nature has her “exaggerations,” likewise! and the first of the genus which ever rose to the stroke of the hammer, has in no degree been misrepresented in its fair proportions, except that the angular projections referred to are not so prominently developed as in other specimens in the author’s collection.

It will readily be inferred from all this that the locality of Dura Den is entitled to much consideration in consequence of the variety of its interesting remains, not to speak of the diversity of views which the remains themselves have occasioned in so many quarters. The Pterichthys, Pamphractus, Homothorax, and Cephalaspis are all of the family Lépidöides, and have such a close affinity in outward form as readily, in mutilated specimens at least, to be mistaken for each other. The appendages of the head, having the appearance of wings, suggested the term pterichthys, the winged fish: the plates covering the body, according to their number and form, gave rise to the generic distinctions; and the species of each have subsequently been determined by minor differences. The external organs in all were enameled, and discover, like the fish of the period, the tuberculated surface. The Pterichthys of the more northern counties vary in size from nearly a foot to an inch in length, and generally the wings of these, so far as they have been figured in works, are extended horizontally and perpendicularly to the body. The Pamphractus of Dura Den are all nearly of a size—about two inches and a half in length,—the wings in every instance depressed and inclined to the sides, and in no instance of the twenty to thirty specimens exhumed from the rock, has the tail been appended, or a fragment of the caudal organ detected. The cephalaspis has only been found in the lower beds of the system, and highly important would be its discovery in the upper, where, however, we have reason to think the new genus Homothorax has been substituted in its place. Mrs. Dalgliesh of Dura, in whose collection we found a Glyptopomus, and a slab containing several impressions of the Pamphractus, has kindly, and with a commendable love of science, informed us that her quarries are freely open for the researches and explorations of geologists, and that every facility will be afforded them in their interesting task.

In addition to the fossils already referred to, I find in the specimens of my collection returned from Neufchâtel, that two are labeled as Diplopterus, new species; two as Glypticus, new species; and one as Holoptychius, new species. This last is now figured in the “Monograph” as the Platygnathus Jamesoni. None of these are described in the narrative of the work, so that until his return from America, where palæontology will unquestionably reap much from his indomitable perseverance, his almost instinctive skill, and vast learning, we cannot expect that M. Agassiz will have leisure either to supplement the deficiencies of his great work, or confirm his former conclusions against the alterations suggested in his absence—suggested certainly in no small degree upon fanciful organization and mistaken assumption.

Platygnathus Jamesoni.

In closing our review of the old red sandstone, we shall briefly state the principles of classification of fossil fishes, as determined by M. Agassiz, from which it will be seen by the earliest types of the marine vertebrata, while admirably suited to the perturbed condition of the element in which the strata were formed, differ widely in their structure from all existing races.

The fishes of the present era, it is well known, are divided into two great classes, the cartilaginous and the osseous. In the former are comprehended the sharks, rays, and sturgeons of our present seas; the latter embrace the salmon, cod, herring, and the various kinds possessed of similar forms. The bony structure in all the cartilaginous class is soft, destitute of fibers, and contains scarcely a trace of earthy or calcareous matter. The osseous fishes, on the other hand, are constructed internally of true bone, composed of calcareous matter, like that of birds and quadrupeds, which is possessed of a fibrous arrangement, of great hardness and capable of long endurance. Now, it would appear that the fishes of the old red sandstone belong almost exclusively to the cartilaginous class. The internal frame was composed chiefly of this soft, soluble substance; hence it is that no portion of the inner body of the fish, in any of the fossil specimens, remains.—The teeth and scales, with fragments of the bones of the head, are all that have survived, but so hard and enduring has been the scaly outer coating, that the figure and contour of the animal have been preserved entire. The specimen of Holoptychius Andersoni, from Dura Den, is still enveloped in its original covering, not a scale in the whole body displaced or missing, the head and belly slightly compressed, while the posterior ridge of the back and tail is sharp and angular.