FOSSIL INVERTEBRATES AND PLANTS 



105 



is massive, a light bar and small (4-pound) sledge hammer are 

 helpful to pry out and break up chunks. If fossils are numerous 

 and easily removed from the rock, a good collection may be made 

 by breaking up the larger chunks on the spot. Generally how- 

 ever, removal of a fossil from its matrix requires more time and 

 facilities than are available in the field. It is best, therefore, to 



Fig. 60. — Views of two brachiopods. 



bring in chunks of fossiliferous rock for more careful breaking 

 in the laboratory. Do not attempt to clean fossils of any kind 

 in the field. 



Fossils usually occur on bedding planes along which the rock 

 cleaves naturally. Fossil impressions will then usually occur 

 on each side of a split piece, hence it is essential that both sides 

 be saved because each impression represents a different part of 

 the animal. 



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