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.