I know not what the savans of Russia have been doing for the last few years; but mainly through the labors of an intelligent tradesman of Thurso, Mr. Robert Dick,—one of those working men of Scotland of active curiosity and well-developed intellect, that give character and standing to the rest,—I am enabled to justify the classification and confirm the conjectures of Agassiz. Mr. Dick, after acquainting himself, in the leisure hours of a laborious profession, with the shells, insects, and plants of the northern locality in which he resides, had set himself to study its geology; and with this view he procured a copy of the little treatise on the Old Red Sandstone to which I have already referred, and which was at that time, as Agassiz’s Monograph of the Old Red fishes had not yet appeared, the only work specially devoted to the palæontology of the system, so largely developed in the neighborhood of Thurso. With perhaps a single exception,—for the Thurso rocks do not yet seem to have yielded a _Pterichthys_,—he succeeded in finding specimens, in a state of better or worse keeping, of all the various ichthyolites which I had described as peculiar to the Lower Old Red Sandstone. He found, however, what I had _not_ described,—the remains of apparently a very gigantic ichthyolite; and, communicating with me through the medium of a common friend, he submitted to me, in the first instance, drawings of his new set of fossils; and ultimately, as I could arrive at no satisfactory conclusion from the drawings, he with great liberality made over to me the fossils themselves. Agassiz’s Monograph was not yet published; nor had I an opportunity of examining, until about a twelvemonth after, the casts, in the British Museum, of the fossils of Professor Asmus. Besides, all the little information, derived from various sources, which I had acquired respecting the Russian _Chelonichthys_,—for such was its name at the time,—referred it to the cuirassed type, and served but to mislead. I was assured, for instance, that Professor Asmus regarded his set of remains as portions of the plates and paddles of a gigantic _Pterichthys_, of from twenty to thirty feet in length. And so, as I had recognized in the Thurso fossils the peculiarities of the _Holoptychian_ (Cœlacanth) family, I at first failed to identify them with the remains of the great Russian fish. All the larger bones sent me by Mr. Dick were, I found, cerebral; and the scales associated with these indicated, not a cuirass-protected, but a scale-covered body and exhibited, in their sculptured and broadly imbricated surfaces, the well-marked Cœlacanth style of disposition and ornament. But though I could _not_ recognize in either bones or scales the remains of one ichthyolite more of the Old Red Sandstone, “that could be regarded as manifesting as peculiar a type among fishes as do the Ichthyosauri and Plesiosauri among reptiles,”[8] I was engaged at the time in a course of inquiry regarding the cerebral