109 



with the peen end of the hammer, or with a flat chisel, and 

 after that with a small prying instrument. A pocket-knife 

 is very serviceable. The thin shale pieces can he easily 

 reduced to the proper size by breaking with the fingers, or 1 >y 

 cutting with a chisel; trimming with the hammer should be 

 avoided. The ultimate trimming and cleaning is to be done 

 in the laboratory. If the specimen is broken, the parts 

 should be wrapped sepeirately and then together, the 

 ii'luinc; beimr left for the laboratorv. 



Collecting from the Weathered Shale. When exposed to 

 rain and sun for some time the shale becomes reduced to 

 clay, and the fossils weather out free. In such cases the col- 

 lector should get down on hands and knees and crawl over 

 the ground, carefully picking up all the good specimens and 

 all the doubtful ones. A small pair of pointed pincers will 

 be found useful for picking up the smaller fossils. When the 

 rock is weathered deeply, it will be found advantageous to 

 carry away a quantity of the clay in bulk, to be looked over 

 in the laboratory. The fossils, as they are picked up, should 

 be placed on a layer of cotton batting, in a box, and not be 

 disturbed again until they reach the laboratory. 



Collecting from the Limestone. Such rocks as the Encri- 

 nal limestone will usually yield their fossils on the blow of 

 the hammer. The rock should be split, if possible, parallel 

 to the bedding plane. If portions of fossils are visible the 

 bulk of the surrounding rock should be trimmed with the 

 hammer, and the further cleaning and developing reserved 

 for the laboratorv. Do not try to break out the fossils in 

 the held. You will probably end by breaking the fossil. It 

 is better to carry some additional rock. When the rock is 

 weathered, the fossils usually stand out in relief, and they 

 may often be obtained by careful manipulation with hammer 

 and chisel. Some rock should always be taken with the 

 specimens, as they can seldom be wholly freed from the 

 matrix without losing in appearance, if not in value. If 

 extensive collections are to be made from the limestones, a 

 sledge hammer is desirable. 



