Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/304

210 Ireland were covered with an ice-mantle at the same time that the Mammoth, Reindeer, and other Postglacial animals were living in the lower and less inclement districts. The evidence of distribution is most important in carrying out this correlation.

§ 9. Relation of Postglacial to Preglacial Mammals. — We have now to discuss the relation of the Postglacial mammals to those that inhabited the counties of Norfolk and Suffolk, and roamed over the ancient plain which extended from the Wash to the mouth of the Rhine in Preglacial times. First of all we must define what the Preglacial mammals are. The following very incomplete list is the result of the examination of all the remains from the Forest-bed in the King, Gunn, Gurney, and Layton collections, and in the Museums of London, Oxford, Cambridge, and Norwich, as well as those in private hands in Cromer and Yarmouth.

List of Preglacial Mammals.

Ursus Arvernensis. U. spelaeus (?Etruscus). Sorex. Mygale moschata. Talpa Europaea. Cervus megaceros ? C. capreolus. C. elaphus. C. Sedgwickii. C. Ardeus.

Bos primigenius. Hippopotamus major. Equus fossilis. Rhinoceros megarhinus. R. Etruscus. Elephas antiquus. E. meridionalis. Arvicola amphibia. Castor fiber. Trogontherium Cuvieri.

Besides these, there are many specific forms which cannot be determined until they have been carefully compared with those of the Pliocenes of the South of France and Lombardy. To this list Dr. Falconer would add the Mammoth ; but a careful investigation into the evidence which was supposed to establish its Preglacial age has convinced me that the inference is faulty. The specimens reputed to come from the forest-bed are, in every case, mere waifs and strays thrown up by the sea between high- and low-water mark, or very possibly derived from the gravels and sands above the boulder-clay. The remains dredged up from the bed of the sea, in the collection of Mr. Owles, establish the fact that a Postglacial deposit containing Reindeer, Tichorhine Rhinoceros, and Mammoth exists off Yarmouth, which very probably was the source whence some of the drifted remains were ultimately derived.

Out of these nineteen animals that inhabited Britain before the deposit of the boulder-clay, all but seven survived the great Glacial change, and formed an integral portion of the Postglacial fauna. The seven exceptions consist of Ursus Arvernensis, Rhinoceros Etruscus, Elephas meridionalis, Cervus ardeus, Cervus Sedgwickii, Trogontherium, and Mygale moschata, the latter of which still flourishes on the banks of the Don and Volga. To these the Pliocene species Rhinoceros megarhinus might have been added, had it not occurred in the Lower brickearths of the Thames Valley. The eleven or twelve survivors bind together indissolubly the Pre- and Postglacial groups, and forbid the idea of the existence of any gap or lacuna which