[13] COLLECTING AND PREPARING FOSSILS SCHUCHERT. 



for more material. Collectors should always bear iu mind that circum- 

 stances may prevent the revisiting of a locality, and should therefore 

 make the best use of i)resent opportunities. 



In the field the first duty is to collect, and it is inadvisable, therefore, 

 to try to become familiar with the details of species. The appropriate 

 place for study is the laboratory. The fossils should be examined only 

 far enough to ascertain whether they are good or bad specimens. 

 ls"otice should be taken of rare sj^ecies which are often fairly abundant 

 along' narrow zones or are found in more or less separated clusters, 

 "When such are met with, it is desirable to search carefully along the 

 zone of occurrences for more. 



Rock trimming. — Do not trim the rock surrounding fossils too closely, 

 since much of the specimen may be covered; moreover, specimens when 

 uot obtained free look far better with a little rock around them. The 

 final trimming should be done after the fossil is developed in the 

 laboratory. 



Hasty collecting. — It is unwise to collect hastily or to try to cover 

 much territory in a short time inless conditions demand it. One 

 large and well-gathered collection is worth far nore than two ^r three 

 small ones. 



Collecting free fossils. — When fossils are found free, lying in the soil, 

 it always pays to get down on the hands and knees and crawl over the 

 ground in search of them, rejecting only poorly preserved or badly 

 broken specimens. Iu so doing the smaller specimens are more likely 

 to be seen, and at the same time collections will not be made hastily. 

 Picking of this kind affords much pleasure and involves less labor 

 than collecting from limestones or sandstones. The collector should 

 remain in such locality until all good material that is visible has been 

 picked U13. 



Molds and casts of fossils. — Rocks having cavities in them, which are 

 the molds of organisms, should always be collected if the cavities are 

 not too much filled with crystals. These molds are of course broken 

 before discovered, but all the pieces should invariably be saved. Do 

 not gum the parts together in the field, but wrap each separately in 

 paper, and put all the parts of one specimen into a single package. 

 The fastening together can be done much better iu the laboratory, and 

 the necessity of having a gum bottle in the collecting outfit will be 

 avoided. 



Internal casts of gastropods (snails) and pelecypods (clams, oysters, 

 etc.) are often of little value when collected alonCj but if the surround- 

 ing matrix preserving the exterior form and ornamentation of the shell 

 is also carefully saved they are more instructive than those showing 

 only exterior characters. Casts of single valves of pelecypods should 

 always be saved. Do not trim these too closely, as they may show 

 impressions of the hinge teeth. Every fragment of a bivalve showing 

 any part of the hinge should be saved. 



