45 



taincd between the South Downs, and the chalk of Isle of Wight, 

 extending westward beyond Dorchester, and eastward as far as 

 Worthing, Bognor giving the name to some calcareous sandstones of 

 which the fossils exhibited are characteristic. These bivalve shells 

 arc most persistent forms of life ; we may trace them up from the 

 Lower Silurian rocks througli the first life of the Paleozoic division 

 of the earth's history, the Meso/oic reptilian age, and find them the 

 contemporanes of the mammals of the Cainozoic or Tertiary, until 

 we, in the human period, see them represented by the mussels, and 

 oysters "alter his kind," in the shops of the fishmongers or on the 

 baiTows of the costermongcrs, and so may look upon the mollusc 

 represented by the oyster as the true native of tlic world, and regard 

 him with increased icspect, and have caiise to swallow him witli a 

 greater relish. These fossil creatures, but low in the scale of 

 creation, lived and died and exhibited the uncertainly of life by 

 dying before they arrived at maturity, thus forming not only an 

 interesting geological specimen, but a moral record of the uncer- 

 tainty of life. 



