265 
Mr. Woodward commented on the remarkable nature of the dis- 
tribution of fossil fishes in the stratified rocks. With rare excep- 
tions, good specimens occurred only in certain definite thin layers 
where they were discovered in great shoals. Fragments were also 
often curiously swept together to form a veritable “ bone-bed,” 
perhaps not more than a few inches in thickness, though extend- 
ing over many square miles of country. Hundreds or thousands 
of feet of sediment certainly deposited in a sea, well tenanted with 
fishes, were not uncommonly destitute of all traces of their 
skeletons except an occasional tooth or scale ; while a local layer 
in the midst of one of these series might unexpectedly reveal a 
rich and varied fauna. On examining specimens from such layers, 
it would often be observed that they exhibited a gaping mouth or 
some signs of contortion at death; there were also geological 
reasons for supposing that they had been quickly covered up with 
sediment. The general conclusion was, therefore, that whole 
shoals of fishes had been suddenly destroyed at these spots either 
by an escape of noxious gases into the sea, or by a cloud of mud 
in some current, or by another unfavourable change in their 
surroundings. The various samples of the fish life of different 
periods had thus been preserved by mere local accident. The 
discovery of them depended again upon mere accident. Hence 
their knowledge of the fishes of past ages consisted entirely of 
little disconnected items culled from widely separated zones 
scattered through the rocks of different parts of the world. The 
period of the Upper Lias happened to be represented by one of 
these instructive zones in at least six districts. There was one in 
Wiirtemberg, another in Bavaria; two were known in France, 
the departments of Calvados and Vassy ; a fifth occurred in the 
cliffs at Whitby, and a sixth in the nodule bed of the Upper Lias 
at Ilminster, Somerset. The careful exploration of the latter was 
undertaken by the late Mr. Charles Moore, whose “ unique collec- 
tion” was arranged inthe Bath Museum. “This beautiful series 
of fossil fishes” was then dealt with by the writer in detail. The 
