FOSSIL VERTEBRATES 



in an equal amount of water. Apply with a small, soft brush 

 either by sprinkling or directly brushing the surface to be hard- 

 ened. 



When fossils occur in sand- 

 stone, limestone, or other con- 

 solidated rocks they can often 

 be quarried out in blocks, fol- 

 lowing the bedding planes and 

 natural seams, and then re- 

 duced in size by chipping off 

 the excess rock. In using this 

 method only the broken ends 

 or exposed sides of the fossil 

 need protection. A strip of 

 burlap dipped in paste, made 

 by mixing flour in water, 

 placed over the exposed sur- 

 faces usually gives ample pro- 

 tection. Often layers of tissue 

 paper pasted on with gum 

 arabic solution serve the same 

 purpose. 



Where the fossils occur in 

 marls, sand, or soil, they are 

 often checked and broken in- 

 to innumerable pieces. To 

 keep these pieces in their nat- 

 ural relationships, and thus 

 avoid permanent damage to the specimen, as well as unnecessary 

 labor in the museum laboratory, such fragile specimens usually 



Fig. 46.— Short-handled pick. 



