102 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jail. 9, 



derived partly from White's Pit (fig. 4), and partly from Blade's Green, 

 between the former and Crayford. 



The comparative abundance of the species from each of these 

 localities is also worthy of note. Bos pr'imigenius is abundant in all ; 

 Elephas primigenius is most abundant at Ilford, Erith, and Crayford ; 

 while E. antiquus is comparatively rare. The latter species on 

 the other hand is most frequently met with in the brick-pits of 

 Grays Thurrock. 



Before, however, I pass on to the range of the mammalia found 

 in these deposits, there remains a most important point to be dis- 

 cussed. Were these animals found in different portions of the same 

 section, the older forms in the lower, the newer in the upper parts? 

 Such, indeed, was the hypothesis upon which Dr. Falconer strove to re- 

 concile the association, at Brentford, of Pliocene species with animals 

 clearly proved to have been of Postglacial age, in the journal of this 

 Society* ; and such was the view he took of the mammalia found at 

 Crayford. Knowing the value of the smallest of his hints, I have 

 over and over again gone over the pit in company with Dr. Spurrell, 

 and with Mr. Flaxman Spurrell, to find evidence for this view, and 

 have come back each time more and more convinced that the mam- 

 malian beds, 4 & 5 of fig. 3, are of the same age, and that the 

 animals found in those beds were living in the Thames Yalley at the 

 time of their deposit. The evidence, indeed, of the association of 

 species at Crayford is corroborated by that of the sections at Ilford 

 and Grays Thurrock. The proof of the tichorhine Ehinoceros being 

 associated with the leptorhine and megarhine species, is to be found 

 in the cabinets of Drs. Cotton and Spurrell, and of Mr. Grantham. 

 For the proof that these three species have been rightly determined, 

 I must refer to the monographs on their dentition in the Natural 

 History Review t, and to that now in the hands of the Geological 

 Society. 



/3. Range of the species. The above list of mammalia enables us 

 to draw some important inferences about the deposits whence they 

 were derived. The interest centres more particularly on the genera 

 which composed Baron Cuvier's group of the Pachydermata, namely, 

 Mephas and Bhinoceros. The Carnivora are such as might have 

 been derived from any Pleistocene cave- or river-deposit in Britain ; 

 and, with one exception (the Cave-Bear), they still survive in some 

 quarter of the world. Of the Ruminants, the great Urus:J: probably 

 survives in our larger breeds of domestic cattle, and the Aurochs or 

 Bison still ranges through the temperate zones of North America, 

 and lingers on in Europe in the Lithuanian forests, under the 

 protection of the Russian government. Extinct in the high northern 

 latitudes of Asia and America, it has left its bones, along with those 

 of the Elk, Reindeer, Musk-sheep, and Mammoth, in the frozen 

 loam that caps an ice cliff in Eschscholtz Bay§, to prove that it 



* Quart. Journ. aeol. Soc. vol. xiv. p. 83, 1857. t Yol. v. p. 399, 1865. 



i See paper by the author in Quart. Journ. Greol. Soc. vol. xxii. p. 391, 1866. 

 § Zool. H.M.S. ' Herald ; ' and Beecliey's ' Voyage to the Pacific,' Appendix by 

 Dr. Buckland. 



