(Communicated by the President.)
The fossil forms, like the living, have their zoological geography more marked in proportion to the development of life upon our planet; and for this reason, even if there were no other, it becomes a duty on the part of those who devote themselves to this branch of science in Spain, to furnish all the aid possible towards an elucidation of the problems which present themselves to the inquirer, notwithstanding the little attention paid to our scientific literature throughout Europe, already deplored by the great geologist De Verneuil[1]. With respect to the subject of this paper, it is necessary to bear in mind that no catalogue has ever been made, even of the summary kind which we are about to present, and that our materials have been collected from a large number of periodicals (Spanish, English, French, and German), extending over a period of about thirty years.
The palæontology of our peninsula presents many interesting features in its relations to the natural conditions of the soil. For example, the migrations of quadrupeds, which have caused the formation, in the greater part of Europe, of deposits of remains at a considerable distance from each other, must have been difficult in the Peninsula from the most remote time, and this has given rise to certain peculiarities in our mammalian fauna. Except by continuity, even in recent time, with the African continent, how can we explain the discovery of the Hyæna brunnea, the leopard, the serval, the lynx, and the deer of Barbary in a cave at Gibraltar?
Other important results of these studies is the discovery in the centre of Spain of remains of the Sivatherium, well-marked, according to Dr. Falconer, and also of Hyænarctos, mentioned by Paul Gervais[2], it having been previously generally believed that these Mammalia had never inhabited Europe, and were confined exclusively to Asia.
The discovery of the types in question confirms the inductions which form the doctrine of modern science, and the theory of the uninterrupted development of organic beings, the Vertebrata beginning with fishes and Labyrinthodonts, and continuing with reptiles, birds, and Mammalia. It is also a confirmation in this part of the world of Owen's arrangement of the four classes of Mammalia.
But it is well known that the importance of the study of fossil Vertebrata is not limited to its palæontological and geological in-
