Vol. 50.] AND SECTIONS BETWEEN TJBMINSTER AND ROMFORD. 4G1 



Dr. Leeson and Mr. Laffan might be divided into two groups, 

 (1) those with bison, and (2) those among which the small ox and 

 dog or wolf occurred. Group 2 he thought might be further distin- 

 guished as (a) the heavy black bones from the silt, and (b) some 

 dirk-coloured, light-weighted bones, the origin of which was open 

 to suspicion. He urged that it was quite impossible that group 1 

 could be newer than group 2, but suggested an explanation of 

 the section which would get over the difficulty, namely, that there 

 was an ancient irregular channel excavated in the older Bison-grayel, 

 and running north of the boss of London Clay shown in the section, 

 and that in this channel the newer black silt had been laid down. 

 He pointed out that the mollusca were all such as now live in our 

 rivers, two out of the eight being named jtuviatilis and amnieum 

 from that fact. He questioned the possibility of distinguishing a 

 small domestic ox from B. longifrons by a fragment of a metatarsal, 

 or a wolf from a dog by one limb-bone, and thought that all the 

 small dark-coloured horn-cores were those of domestic cattle. 



Mr. E. T. Newton remarked on the interest attaching to this 

 new discovery of such abundant remains of reindeer in the Thames 

 Valley gravels to the west of London ; a species which, as Prof. W. 

 Boyd Dawkins had pointed out, had not been met with in these 

 gravels eastward of London. With regard to the single bone of Bos 

 longifrons, he could not accept it as good evidence of the occurrence 

 of that form in the same bed with bison and reindeer, and felt 

 sure that it must have been derived from some newer deposit. 



Mr. Lewis Abbott could not help thinking that Mr. Holmes had 

 been very bold in attempting to construct a river some 80 miles 

 long from a single section. The Boulder Clay was coincident 

 with the present valley and occurred at various heights down to 

 about 50 feet on the northern side, and lower still on the southern 

 side: if that did not indicate a valley, he failed to see what would. 

 But why a pre-Thamesian date was claimed for it he could not 

 understand. That the Boulder Clay extended into the Thames Valley, 

 and even over it, was evinced by the large number of Northern fossils 

 and rocks found south of that river. He considered the paper one 

 of great interest and importance. 



Preferring to Messrs. Leeson andLaffan's paper, he could not agree 

 with the lacustrine origin of the beds under consideration. The list 

 of mollusca commenced with a genus which would almost settle this 

 point : the facies was not lacustrine but sluggish-water, nor was the 

 coarseness of the gravels consistent with a pond or lake origin. The 

 section was, in almost all respects, similar to that exposed at the 

 new Admiralty Offices, where a lateral ridge had existed ; upon 

 the hugging of the southern shore by the stream a backwater was 

 left, where a sediment of a more muddy nature was laid down : in 

 this the unique animal-remains were deposited. It was at about 

 the same relative level as that of the Admiralty which produced 

 Salicc polaris, and was probably of the same age. At the Admiralty 

 section the upper gravels were in all probability much newer than 

 the lower beds, and he ventured to think that also was the case in 

 this instance. 



Q. J. G. S. No. 199. 2 1 



