whose geological attainments, as one of the authors of the _Guide Book_, I have lately had occasion to refer. I had now corresponded for several years with a little circle of geological friends, and had described in my letters, and in some instances had attempted to figure in them, my newly-found fossils. A letter which I wrote early in 1838 to Dr. Malcolmson, then at Paris, and which contained a rude drawing of the _Pterichthys_, was submitted to Agassiz, and the curiosity of the naturalist was excited. He examined the figure, rather, however, with interest than surprise, and read the accompanying description, not in the least inclined to scepticism by the singularity of its details. He had looked on too many wonders of a similar cast to believe that he had exhausted them, or to evince any astonishment that Geology should be found to contain one wonder more. Some months after, I sent a restored drawing of the same fossil to the Elgin Scientific Society. I must state, however, that the restoration was by no means complete. The paddle-like arms were placed further below the shoulders than in any actual species; and I had transferred, by mistake, to the creature's upper side, some of the plates of the _Coccosteus_. Still the type was unequivocally that of the _Pterichthys_. The secretary of the Society, Mr. Patrick Duff, an excellent geologist, to whose labors, in an upper formation of the Old Red Sandstone, I shall have afterwards occasion to refer, questioned, as he well might, some of the details of the figure, and we corresponded for several weeks regarding it, somewhat in the style of Jonathan Oldbuck and his antiquarian friend, who succeeded in settling the meaning of two whole words, in an antique inscription, in little more than two years. Most of the other members looked upon the entire drawing, so strange did the appearance seem, as embodying a fiction of the same class with those embodied in the pictured griffins and unicorns of mythologic Zoölogy; and, in amusing themselves with it, they bestowed on its betailed and bepaddled figure, as if in anticipation of Agassiz, the name of the draughtsman. Not many months after, however, a _bona fide_ _Pterichthys_ turned up in one of the newly discovered beds of Nairnshire, and the Association ceased to joke, and began to wonder. T merely mention the circumstance in connection with a right challenged, at the late meeting of the British Association at Glasgow, by a gentleman of Elgin, to be regarded as the original discoverer of the _Pterichthys_. I am, of course, far from supposing that the discovery was not actually made, but regret that it should have been kept so close a secret at a time when it might have stood the other discoverer of the creature in such stead.