76 



course of the present valleys, and have a direction of transport 

 coincident with that of the present rivers. 



2. — That these beds contain in places, land and fresh-water 

 shells in a perfect and uninjured condition ; and also the 

 remains, sometimes entire, of land animals of various ages. 



3. — That the extent and situation of some of the beds of 

 gravel so much above the existing valleys and river channels, 

 combined with their organic remains, point to a former condition 

 of things when such lands constituted the lowest ground over 

 which the waters passed. 



4. — That the size and quantity of the debris afford evidence 

 of great transporting power, whilst the presence of fine silt, 

 with land shells, covering all the different gravel beds, and 

 running up the Coombes, and capping the summit of some 

 adjacent hills to far above the level of the highest of these beds, 

 point to floods of extraordinary magnitude." 



And now, before proceeding to the more direct subject matter 

 of my paper, permit me to acknowledge most fully the very 

 great assistance I have received from Mr. Etheeidge, in con- 

 structing the map, making the vertical sections, and naming the 

 rock specimens and fossils, and to whom I am further indebted 

 for many valuable suggestions ; also to my friends our President, 

 Sir W. Guise, Bart., the Eev. W. S. Symonds, Dr. Wright, 

 Messrs. Tomes, Kieshaw, Platne, Witchei,l, Bellows, my 

 old companion and instructor, Mr. John Jones, and Mr. Boyd 

 Dawkins, who classified the Mammalian remains. I have 

 further to thank Mr. Joedan, of Jermyn Street, for hia 

 admirable execution of the map. 



With the late Mr. Steickland I regard the term " Drift " 

 to denote all those superficial accumulations of transported 

 materials, which are so circumstanced that they cannot have 

 been produced by the tranquil causes which are in daily operation 

 in the district, and which I propose to divide as follows : — 



Pirst, — I adopt the general name of !N^orthern drift, which, 

 although sufiiciently comprehensive, I acknowledge is far from 

 being definite or satisfactory. It is composed of Quartzose 

 pebbles, long since shown by Sir E. Mueohison to be dei'ived 



