terest, but extends to the scientific investigation of the present zoological geography of this group. Whatever may be our opinion upon the theory of the specific centres which individual organic forms may have taken as their point of departure, it will always be of advantage to the student to find in every locality the prehistoric ancestors of its fauna; to use the comparison of Lyell, the connexion between the present and the fossil forms, particularly in the case of the Mammalia, is the same as that between the different dialects which proceed from one primitive language. It is no longer possible to doubt that a great number of the present forms of animal life have been in existence since the beginning of the Quaternary formation, and that there has been an almost insensible transition from the fauna of that period to that of the present, it being nearly impossible to differentiate the palæontology of the two periods. This opinion has been supported by Owen in his work on British Mammals and Birds.
From this point of view nothing can be more worthy of detailed investigation than the rich bone-deposits of Old Castile, which abound with remains of the present and immediately preceding races, and from which upwards of five hundred thousand arrobas (or quarters) of bones, some fossil, some recent, have been obtained for commercial purposes only. Among these bones have been discovered artificial objects, such as flint knives of the reindeer period, polished axes, and objects of metal.
The investigations in Spain are important when viewed with reference to the subject of extinction of species, particularly those that were contemporary with man in the period termed by Lubbock Palæolithic, and which is marked by the existence of animals that have since disappeared. Taking, for example, the Urus (Bos primigenius), we have clear proofs of its having existed in the Peninsula until a very recent period—among them a philological proof in the name of Monsuri, applied to a small hill on the banks of the Tagus[1]. It is also important to bear in mind that remains of the mammoth have been found in various parts of Spain—in the caverns of the Pyrenees, in the centre in Madrid, and in the south near the shores of the Mediterranean, a position further south than Home, which has generally been considered the southern limit of the tract in in which the bones of this animal are found. The same may be said of the Rhinoceros tichorhinus, which has, without doubt, been discovered in two different places in the north of the Peninsula.
To sum up the results of the investigations made among the fossil Vertebrata in Spain, we may mention that they arc not represented until we come to the Carboniferous formations (where wo have found impressions of fishes having the tail heterocercal), in coal-shales in the province of Leon, together with many impressions of ferns, which have been carefully studied[2]. Consequently no
