54 INVERTEBRATE PALAEONTOLOGY 



first attention should be paid to weathered rock-surfaces 

 that are usually to be found on natural or artificial 

 sections. Not until this examination is complete is 

 actual quarrying advisable. In most cases, if fossils 

 do not appear on decaying surfaces, they are less likely 

 to be seen in newly fractured matrix. If a portion of 

 a fossil is seen protruding from hard rock, its surround- 

 ings should be carefully studied with a view to finding 

 cracks or other lines of weakness along which fractures 

 can be made. In all cases where hammering is required, 

 care should be taken to let the blows fall as far from 

 the specimen as is consistent with its ultimate extraction. 

 Never attempt to break out the fossil, but aim to collect 

 the piece of rock in which it is embedded. When 

 possible, it is a valuable safeguard to keep one hand 

 over the specimen while using the hammer, since it may 

 fly off unexpectedly and be lost to sight. 



It is often easier to pick up fossils from the talus 

 or quarry-heaps than to dig them out from a rock-face, 

 and still less exhausting to purchase them from the 

 quarrymen. Such aids to collecting should not be 

 ignored ; but it is essential to remember that specimens 

 thus acquired have not the same certainty of strati- 

 graphical horizon. However, it is often possible to 

 trace the bed from which such fossils have come, usually 

 by comparison of their matrix with that of the main 

 section. 



If minute fossils are required (e.g. Foraminifera, 

 Ostracoda, or small shells), collection of individual 

 specimens is clearly infeasible. Any friable or rotted 

 layer may contain such organisms, and it is best to 

 transfer the loose material to tins in bulk, taking the 

 risk as to whether later examination will prove it pro- 

 lific or barren. In some cases it is possible to gain 

 some indication of the quality of such material before 



