But no man who enters the geological field in quest of the wonderful, need pass in pursuit of his object from the true to the fictitious. Does the reader remember how, in Milton's sublime figure, the body of Truth is represented as hewn in pieces, and her limbs scattered over distant regions, and how her friends and disciples have to go wandering all over the world in quest of them? There is surely something very wonderful in the fact, that, in uniting the links of the chain of creation into an unbroken whole, we have in like manner to seek for them all along the scale of the geologist;--some we discover among the tribes first annihilated--some among the tribes that perished at a later period--some among the existences of the passing time. We find the present incomplete without the past--the recent without the extinct. There are marvellous analogies which pervade the scheme of Providence, and unite, as it were, its lower with its higher parts. The perfection of the works of Deity is a perfection entire in its components; and yet these are not contemporaneous, but successive: it is a perfection which includes the dead as well as the living, and bears relation, in its completeness, not to time, but to eternity. We find the organisms of the Old Red Sandstone supplying an important link, or, rather, series of links, in the ichthyological scale, which are wanting in the present creation, and the absence of which evidently occasions a wide gap between the two grand divisions or series of fishes--the bony and the cartilaginous. Of this, however, more anon. Of all the organisms of the system, one of the most extraordinary, and the one in which Lamarck would have most delighted, is the _Pterichthys_, or winged fish, an ichthyolite which the writer had the pleasure of introducing to the acquaintance of geologists nearly three years ago, but which he first laid open to the light about seven years earlier. Had Lamarck been the discoverer, he would unquestionably have held that he had caught a fish almost in the act of wishing itself into a bird. There are wings which want only feathers, a body which seems to have been as well adapted for passing through the air as the water, and a tail by which to steer. And yet there are none of the fossils of the Old Red Sandstone which less resemble any thing that now exists than its _Pterichthys_. I fain wish I could communicate to the reader the feeling with which I contemplated my first-found specimen. It opened with a single blow of the hammer; and there, on a ground of light-colored limestone, lay the effigy of a creature fashioned apparently out of jet, with a body covered with plates, two powerful looking arms, articulated at the shoulders, a head as entirely lost in the trunk as that of the ray or the sun-fish, and a long, angular tail. My first-formed idea regarding it was, that I had discovered a connecting link between the tortoise and the fish--the body much resembles that of a small