removed without injuring what it overlies; but you will find them in the smaller cast which accompanies the others, and which, as shown by the thickness of the plate in the original, indicates their size and form in a large individual, very characteristically shown. So coral-like is their aspect, that if it was from such a cast, not a fossil (which would, of course, exhibit the peculiarities of the bone), that Lamarck founded his genus Monticularia, I think his apology for the error might almost be maintained as good. I am sorry I cannot venture on taking casts from some of my other specimens; but they are exceedingly fragile, and as they are still without duplicates I am afraid to hazard them. Since publishing my little volume I have got several new plates of Asterolepis,--a broad palatal plate, covered with tubercles, considerably larger than those of the creature's external surface,--a key-stone shaped plate, placed, when in situ, in advance of the little plate between the eyes, which form the head and face of the effigy in the centre of the buckler,--and a side-plate, into which the condyloid processes of the lower jaw were articulated, and which exhibited the processes on which these hinged. There are besides some two or three plates more, whose places I have still to find. The small cast, stained yellow, is taken from an instructive specimen of the jaws of coccosteus, and exhibits a peculiarity which I had long suspected and referred to in the first edition of my volume on the Old Red Sandstone in rather incautious language, but which a set of my specimens now fully establishes. Each of the under jaws of the fish was furnished with two groups of teeth: one group in the place where, in quadrupeds, we usually find the molars; and another group in the line of the symphyses. And how these both could have acted is a problem which our anatomists here--many of whom have carefully examined my specimen--seem unable, and in some degree, indeed, afraid to solve. I have written to the Messrs. Gould, Kendall & Lincoln to say that the third edition of the "Footprints" differs from the first and second only by the addition of a single note and an illustrative diagram, both of which I have inclosed to them in my communication. I anticipate much pleasure from the perusal of your work on Lake Superior, when it comes to hand, which, as your publishers have intrusted it to the care of a gentleman visiting this country, will, I think, be soon. It is not often that a region so remote and so little known as that which surrounds the great lake of America is visited by a naturalist of the first class. From such a terra incognita, at length unveiled to eyes so discerning, I anticipate strange tidings. I am, my dear sir, with respect and admiration, very truly yours, HUGH MILLER.