1 8 Stopes, a Neiv Fern from the Coal Measures. 



other plant debris. Each probably represents a drifted 

 plant, which had become water-logged and sank among 

 the shells on the sea bottom. This minimises chance 

 association among plants so preserved in one nodule, 

 for the vissicitudes of drifting would tend to separate any 

 parts which were not organically connected. Hence the 

 association of sporangia with the vegetative organs in the 

 present instance is of much more value than it would be 

 in the case of most fossils which have been preserved 

 together with the mass of debris of the forest floor. In 

 sections, the matrix of the nodule contains numbers of 



Fi<r. 2. Small portion of the central axis sliewing the "shattering" 

 of the tracheides. (Slide T. 4.) 



goniatites of varying size, some extremely small and only 

 revealed by the microscope ; they are embedded in what 

 appears to be a fine mud which is nearly opaque in 

 section, but which does not penetrate the tissues of the 

 plant. Where, as is frequently the case, parts of petiole 

 or axis are wanting, they are replaced by a clear, cream- 

 coloured calcite frequently shewing crystalline structure. 

 The preservation of the plant tissues is in parts excellent, 

 but these good regions are tryingly local, and neighbour- 

 ing sections may show a mass of calcite in place of the 

 continuation of the tissues. Local " carbonisation " also 

 occurs, which, though generally blurring the tissues, has 



