VOL. XIV.(3) THE PRESIDENT’S ADDRESS 185 
shells” at Kempsey and Upton, and he quotes Jabez Allies, 
who states, that at Bromwich Hill, a suburb of Worcester, 
he found marine shells in gravel with a tooth of Rhinoceros. 
It is needless to give further details of shelly deposits 
in the lower Severn Valley. I admit their occurrence, 
but I hold that they do not prove what they have been 
supposed to prove. 
It is one of the commonplaces of geological science, 
that the species entombed in a sedimentary deposit are a 
test of its age; but this test is obviously not applicable, if 
they have been derived from an older formation. In the 
gravels under consideration, we find fossils of three kinds, 
viz. :—(1) Jurassic species, (2) Recent marine shells, and 
(3) Bones of mammals, recent and extinct. No one 
would contend that the gravels are of Liassic age, because 
they contain specimens of Gryphea zncurva, for they are 
admittedly derived from the Lias, and are usually water- 
worn. The mammalian bones, on the other hand, may 
be accepted as a test of the age of the gravels, since they 
normally occur in deposits on the lower slopes of our 
recent valleys, and frequently are quite unworn. But 
what shall we say about the marine shells? I reply that 
they, like the Lias fossils, are derived from a more ancient 
formation, and prove nothing of the age or origin of the 
strata in which we find them. 
I was first led to suspect the derivative origin of these 
shells by the study of a section near Worcester, which I 
have since ascertained to be on Bromwich Hill, where Mr 
Allies obtained marine shells and the tooth of Rhznoceros. 
It occurs in a gravel-pit at between 70 and 80 feet above 
sea-level. In a bed of sand I found a fragment of a shell, 
probably Cavdium. The great majority of the pebbles in 
the gravel are of rocks which were very familiar to me in 
Shropshire. The most common kind was quartzite, 
derived from the Trias of the Midlands. It was also easy 
