variety of the ocean life of that period, as the mate- 

 rial dredged up from the bottom of the present seas, 

 did of the existing fauna. 



It was not until some time after that I had dis- 

 covered this material , that I became aware that Mr. 

 Joseph Wright, F. G. S. of Belfast had also, a few 

 years previously, ascertained, that many of the flints 

 in the chalk of the North of Ireland, contained depo- 

 sits, similarly rich in fossils, and that he had published 

 a list of those which he had discovered in the con- 

 tents of these stones. As, however, it did not ap- 

 pear that these microzoa had been previously noticed 

 in the chalk Flints of the East of England, a locality 

 several hundreds of miles distant, and in strata now 

 entirely discontinuous from the beds of the Irish chalk, 

 I determined to work out the contents of my disco- 

 very for the sake of seeing how far the fossils from 

 these two places agreed with each other and with 

 those of the cretaceous strata of Germany and else- 

 where. Further I hoped to be able to show the 

 great variety of the various forms of life which in 

 such a small quantity of material and from a single 

 locality were mingled together in the mud of the Cre- 

 taceous ocean, and consequently I resolved to limit 

 my investigation to the contents of this single hollow 

 flint. 



I prepared this flint meal, if thus it may be term- 

 ed, by carefully washing away the finer particles; 

 which reduced it when dry to about 3 or 4 ounces in 

 weight. By this means the fossils were brought in- 

 to a small compass, but even so, it involved pretty 

 constant work for several weeks to look over and pick 

 out, under a strong simple lens, the principal fossils 



