Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/164

74 Budleigh species, occurs abundantly in the reddish sandstone, or quartzite, of May, near Caen, in Normandy, a rock referred by most geologists to the Caradoc, and asserted by Mr. Salter to lie above the Armorican Sandstone with Lingula Lesueuri—a formation seemingly part of the great slaty series of Angers, therefore far underlying the May sandstone; he further adds, "In brief, then, the mass of the Budleigh-Salterton fossils are Norman types of the May Sandstone, and some belong to the 'Gres Armoricain;' several of the species have been already named in France, and some of the more conspicuous shells, though apparently undescribed, are characteristic of the rocks on both sides of the Channel." I must nevertheless observe that very few of the forty species of Brachiopoda found at Budleigh-Salterton have hitherto been obtained from the Middle and Lower Silurian rocks of Normandy and Britain. Mr. Vicary has never yet found Orthis redux?, var. budleighensis, associated with Lingula Lesueuri; indeed very rarely do we find this last-named shell in company with other Brachiopoda in the same pebble. It is, moreover, not easy to be certain about the correct identification of some of the incomplete internal casts and impressions of the Budleigh species of Orthis and Strophomena, which may be, most probably, Devonian forms; so much do the species of those genera in the two periods sometimes resemble each other, notwithstanding their specific distinctness.

Now, as it is quite certain that all the species found in the same pebble with one or more of those forms believed to be correctly determined must be of the same age, we shall find, as far as our present imperfect knowledge will carry us, that only three or four of the species of Brachiopoda have been, with some degree of certainty, referred to the Lower-Silurian period; while eight or nine, supposed to be Silurian, and which have occurred in the same stones with Orthis redux, Barr.?, var. budleighensis, must remain for the present of undetermined age, although they possess much more of the Devonian than of the Silurian facies. Twelve or thirteen are unquestionably Devonian shells, while the remaining fourteen, either being new or not having hitherto occurred or been found with any of those already recorded as Silurian or Devonian, cannot yet with certainty be correctly located; but they seem, to my eye, to possess in most cases a very decided Devonian aspect.

It is highly probable that when the species of the other classes also occurring in these pebbles shall have been carefully and criticallyexamined, the true age of the fossils generally will be established, as the whole series must be taken into consideration before we can expect to arrive at any definite conclusion. But all tends to show that the great bulk of the fossiliferous pebbles at Budleigh