198 miss m. c. stopes on [May 1909, 



rivers are too strong and rapid to allow of boating, and the sides 

 are often too steep to permit of one's walking along them ; but by 

 frequent crossings through the water it is possible to navigate 

 them on foot. This physical difficulty, and the trouble and expense 

 of carrying specimens and tents by coolies, as also the relatively 

 small amount of exposure which the geologist has to work upon, 

 account for several of the uncertainties that exist about these beds. 



Among the large waterworn pebbles numerous specimens of 

 plant- and ammonite-containing nodules are to be found, many 

 of which have proved to contain well-petrified plant-fragments. 

 Of the many nodules which lie washed out in the course of the 

 stream, the plant-containing nodules of the Upper Cretaceous beds 

 are recognizable by the ammonites enclosed in them, as well as 

 by the special creamy - yellow colour which they have when 

 weathered. They vary much in size, some being an inch or two 

 in diameter, others a foot or more. The very largest that I 

 observed was 5 feet in diameter, but it was partly broken, and as 

 its shape was that of an almost perfect oblate spheroid, it must have 

 measured 6 feet when complete. Up to 2 feet in diameter was no 

 uncommon size, but those measuring over 2 feet were very few. 

 In several of the large concretions lying in situ, both plants and 

 ammonites were seen embedded. 



The identity in age of the fossils in the nodules and of the shales 

 enclosing them could not be assumed ; but, although the plant-frag- 

 ments were not well enough preserved to be recognizable, animal 

 fossils were found in the shales of the same species as those in the 

 nodules. Hence the fossils in the nodules, both plant and animal, 

 can be fairly considered as representing the life of the period in the 

 locality of these deposits. 



In some of the nodules, when broken open, could be seen small 

 fossils embedded in distinct layers, showing that the concretions 

 had formed round the organic remains as they lay stratified in the 

 shale, just as was found to be the case in the ' roof-nodules ' from 

 the Coal-Measures (see Stopes & Watson, op. cit. p. 180). 



Not far from the very large nodules lying in situ I observed 

 thicker, sandier slabs than usual in the shale, on which were 

 numerous worm-tracks and sun-cracks, which seemed to afford 

 good evidence that the nodules had been formed at no great distance 

 from a shore. The shales were practically free from any of the 

 elements of a breccia or conglomerate, so that the coast was pre- 

 sumably neither a rocky nor a pebbly one, but rather protected, 

 with fine sandy and muddy deposition. 



III. Microscopic Structure oe the Nodules. 



It is characteristic of the true ' coal-ball ' that the mineral matrix 

 is homogeneous, and there are no intrusive grains of quartz, or even 

 of mud. They are approximately pure carbonate-concretions formed 

 in a mass of plant-tissue. The ' roof-nodules/ on the other hand, 



