x INVERTEBRATE PALAEONTOLOGY 



(C) THE PRESERVATION OF FOSSILS 



PAGE 



I. Complete or Unchanged Preservation . . 39 

 II. Casts and Moulds . . . . . .42 



III. Petrifaction 



(a) By Infilling . . . . -44 



(&) By Molecular Replacement . . .46 



IV. Distortion and Disfigurement . .46 

 V. Impressions and Tracks . . . . .48 



CHAPTER III 



TECHNIQUE 



(A) COLLECTING 



I. Purpose in View . . . . . -5 



II. Regard for Stratigraphical Position . . -52 



III. Large and Minute Fossils . . . . -53 



IV. Field Preparation .... -55 

 V. Field Labelling and Packing . . . .56 



(B) PREPARATION 



I. Need for Patience .... -58 



II. Separation of Fossils from Matrix . . -59 



III. Dissection of Fossils . . . . .62 



IV. Staining ..... .65 



V. Storage and Preservation . .66 



(C) TAXONOMY . . .67 



CHAPTER IV 



GEOLOGICAL PALAEONTOLOGY 



(A) STRATIGRAPHICAL 



I. Zones and Hemerae . . . . -73 



II. Characteristic Fossils . . . . 78 



