248 Mr. J. Lycett on the Fossil Conchology of the how a narrow strap-formed apparatus is to work out a circular hole. But having this powerful siliceous organ at hand, cer-tainly capable of penetrating calcareous substances, it would be unlike the direct and simple operations of nature were another one provided. It is more likely that some mode of application is effected by which the ordinary prehensile tongue of the Gaste-ropod is turned into a rasping or drilling instrument. The wearing down of the anterior spines appears favourable to this opinion. EXPLANATION OF PLATE VIH. Fig. 1. A portion of the epidermis from the anterior cushion-like swelling of the mantle of Saxicava rugosa, seen in the compressor, exhibiting large crystalline bodies. =— 2. Some of the crystalline bodies from the same after having been six hours in nitric acid. — 3. The foot and mantle of a small foreign Patella found dried up in an excavation, showing the arrangement of the crystalline bodies. — 4. A group of the same crystalline bodies more highly magnified. — 5. Four of the same bodies exhibiting radiating fractures caused by the action of the compressor. — 6. A portion of the convex surface of the foot of Teredo norvegica, as seen in the compressor, exhibiting crystalline bodies. — 7. A group of the same bodies more highly magnified. XXVI. — Notes on the distribution of the Fossil Conchology of the Oolitic Formations in the vicinity of Minchinhampton, Glouces-tershire, By John Lycett, Esq.* The following remarks have been written chiefly with a view to illustrate the contents of the author^s cabinet, premising that the objects in question constitute materials fitted rather for private study than for public demonstration. The bones of gigantic Saurian reptiles, of fishes, the shells of great Cephalopods, are appreciated even by the uninstructed spectator. They speak to his senses of a creation distinct from that which he sees around him, and he is prepared to hear of further wonders when the voice of comparative anatomy tells him of their organization and consequent habits. None of these fall within the scope of my remarks ; they are absent : we know that they existed contempo-raneously with the deposition of these rocks and their included fossils : Stonesfield in this country, Pappenheim and Solenhofen in Germany assure us of this. Speaking with the caution which the subject demands, it may be asserted that the conditions of sea-bottom in our neighbourhood, though varying considerably during the time which was required for an accumulation of 400 feet in vertical thickness of solid rock, and the creation and ex-* Read before the Cotteswold Naturalists' Club, August 8, 1848.
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