210 REPORT — 1844. 



the beak, tai'sal scuta, claws, remiges and rectrices, are of course effaced in a 

 fossil state, and the study of the bony skeleton has not yet been carried into 

 sufficient detail (except in the case of some very isolated groups) to serve as 

 the basis of generic definitions. The fossil skeletons of birds will neverthe- 

 less often guide us to the family or even the subfamilt/ to which the speci- 

 mens belong, and as the science progresses a greater amount of precision will 

 no doubt be attained. 



Birds, like Mammalia, appear not to have generally " multiplied and re- 

 plenished the earth " until the commencement of the Tertiary epoch. Ex- 

 amples of their existence at an earlier period do indeed occur, but though 

 the evidence of this fact is indisputable, yet the information it conveys is 

 vague and obscure, and we look in vain for such grand palseontological dis- 

 coveries as those which in the classes lieptilia, Pisces, Mollusca and Crusta- 

 cea, have added whole families and even orders to the zoological system. 



Many geologists have supposed that the rarity of fossil Mammals and Birds 

 in the Secondary rocks is owing to the improbability of their becoming im- 

 bedded in marine deposits, and not to their non-existence altogether. So far 

 however as it is possible to draw a conclusion from negative evidence, there 

 seem very strong reasons for believing that, in the European hemisphere at 

 least, neither Birds nor Mammals were called into existence prior to the middle 

 of the oolitic period. Let us take the case of the Coal-Measures, a formation 

 of vast extent, and which is proved to have been in some cases a ten-estrial 

 deposit, and in others to have been formed in the immediate vicinity of dry 

 land. Yet this vast series of beds, Avhich has been quarried by man to a 

 greater extent than any other, and which contains the remains of Plants and 

 even of Insects in the most perfect state of preservation, has never yet 

 afforded the slightest indication of a Mammal or a Bird. When we contrast 

 this fact with the frequent occurrence of bones of these animals in recent 

 peat-bogs, and in deposits, both marine and lacustrine, of the tertiary epoch, 

 we can hardly attribute the absence of such remains in the Coal-Measures to 

 any other cause than to the non-existence at that period of the two highest 

 classes of Vertebrata. The Triassic or New Red Sandstone series leads in 

 the European quarter of the globe to the same conclusion. We there find, 

 in Germany and in Britain, evidences of ancient shores and sandbanks, ex- 

 posed (probably during the recess of the tide) to the sun and the rain, and 

 presenting the footprints of numerous reptiles which walked upon their sur- 

 faces. Now these are the localities to which aquatic birds, as well as certain 

 mammals, love to resort, yet no traces of such animals have yet been met 

 with in any ascertained triassic rock of the eastern hemisphere. The Lias 

 and Lower Oolite again, though strictly marine deposits, contain in many 

 places the remains of plants or of insects which have tioated from adjacent 

 shores, but invariably unaccompanied by any fragments of birds or of mam- 

 mals. Tn the Stonesfield slate we find the first and the only indication of 

 Mammalian remains in the whole secondary series ; but the bones from that 

 formation, which were once referred to birds, have been proved to belong to 

 Pterodactyles, and no unequivocal examples of birds occur till we reach the 

 horizon of the Wealden beds, where they are exceedingly rare, and appa- 

 rently unaccompanied by Mammalia. 



In the American continent however a remarkable case occurs, which seems 

 to prove the existence of birds at a period long anterior to their first appear- 

 ance in our hemisphere. I allude to the now well-known instance of Ornith- 

 ic/mites, or birds' footmarks, in the sandstone of the Connecticut valley, 

 first discovered by Dr. J. Deane, and described by Prof. Hitchcock in the 

 * American Journal of Science,' 1836-37. (See also Buckland's ' Bridgewater 



