(j guide to the fossil INVEllTEBEATE ANIMALS. 
^llery XI. already in Case 2, where are exhibited specimens from the 
Chalk, many forms have an unfamiliar appearance, and 
indeed belong to types of life which no longer exist. A like 
strangeness characterises the Jurassic fossils, but is still more 
Wall-cases noticeable among the older rocks : thus Case 4 contains some 
of the curious plants from the Coal Measures, while in Case 5 
are fragments of Old lied Sandstone with the strange fishes 
characteristic of that period. Closer inspection would show' 
that this change was gradual and continuous, and that each 
of the successive beds of rock was characterised by fossils 
difl'ering from those found in the lieds above and below. 
Sometimes the bed itself may change in mineralogical 
character, while tlie fossils remain the same. Therefore, 
when once a geologist knows the fossils cliaracteristic of the 
various strata he can, if set down in any part of the country, 
readily determine on which bed in the geological series he is 
standing, if only he can find a few fossils. 
Between The credit of first recognising this important fact is due, 
at least so far as British geology is concerned, to William 
Smith (Plate II), whose bust, a copy of that by Chantrey in 
All Saints’ Church, Northampton, is on the eastern wall of 
the Gallery, ’hhe son of a small farmer and mechanic. Smith 
was born at Churchill, Oxfordshire, in 1769, and at an early 
age collected the fossils that occur in the rocks around his 
home. When the boy was eight years old his father died, 
leaving him to the care of an uncle who, noticing the 
studious habits of his nephew, gave him some money to buy 
books. By means of tliese he taught himself to such 
purpose that at the age of eighteen he oljtained employment 
as a land surveyor in Oxfordshire and the neighhouring 
counties and, in 1793, was appointed to survey the course 
of the intended Somersetsliire coal canal near Bath. Six 
years’ work on this canal, added to his previous knowledge, 
enabled him to prove that the strata met with in this 
district followed each ()ther in a regular and orderly 
succession, each bed being marked 'by its own characteristic 
fossils, and having a general tendency to slojie or dip t(^ the 
S.E. That this succession was no local phenomenon, and 
that the same fossils were throughout characteristic of the 
same beds, was subsequently proved by Smith in his 
journeyings over the greater part of Britain. Ihe surveys 
made on these journeyings enabled him, in 1815, to publish 
the large map exhibited on the right hand of the entrance 
to this Gallery. This, the first geological map of England 
