188 Reports and Proceedings — Geological Society of London. 



the Kajmahal Series of India, in Central Japan, and at Bornholm. 

 Its probable taxonomic position is best expressed by placing it as 

 a member of the Cycadophyta. 



The author proceeds to a comparison of the Bornholm, Indian, 

 Japanese, and English floras ; and as resemblances are masked by 

 the use of different generic or specific names for plants which are 

 either identical or represent closely allied members of the same 

 family, a special list of these floras has been prepared, in which, 

 while the names at present in use are indicated, it is pointed out 

 where obscured identities or resemblances exist. Prom this com- 

 parison the author concludes that there was a greater similarity 

 between the vegetation of Eastern and Western regions, during 

 part at least of the Mesozoic Era, than is usually admitted ; while 

 the differences between Mesozoic floras of approximately the same 

 geological age are for the most part slight and unimportant, when 

 their wide geographical separation is considered. Equisetaceous 

 plants are practically ubiquitous ; several ferns of apparently the same 

 species occur in the Far East and in Western Europe ; cycadaceous 

 plants are represented by cosmopolitan types, and the same may be 

 said of the genus Araiicarites and other members of the Coniferee. 

 The most noteworthj' exceptions are afforded by the Mesozoic repre- 

 sentatives of the two isolated recent ferns Matonia and Dipteris ; 

 these two families — each with a surviving genus — played a con- 

 spicuous part in the vegetation of the Ehgetic and succeeding Jurassic 

 Epochs in Europe, and to a less extent in North America, but there 

 are no satisfactory records of their existence in India or Japan. 

 A similar state of things is illustrated by the Ginkgoales, the class 

 of which the ' maidenhair-tree ' of China and Japan forms the solitary 

 survivor; the abundance of both Ginkgo and Baieram the Mesozoic 

 of Europe is in striking contrast to their almost complete absence 

 iin India. 



2. "The Amounts of Nitrogen and Organic Carbon in some Clays 

 and Marls." By Dr. N. H. J. Miller, F.C.S. (Communicated by 

 Sir John Evans, K.C.B., D.C.L., F.E.S., For. Sec. G.S.) 



Analyses of soils are given to show that, under most conditions, 

 decaying vegetable matter in soil tends to become more nitrogenous, 

 on account of the greater ease with which gaseous compounds are 

 formed with carbon than with nitrogen. Hilgard's experiments 

 throw light on the effects of extreme conditions of climate, the 

 amount of soluble humus being much greater in soils in humid than 

 in arid climates; thus, although the total amount of soluble nitrogen 

 does not vary much, the percentage of it in the humus varied very 

 considerably in the two cases. The large areas of peat-land known 

 as ' Hochmoor ' contain larger proportions of carbon and nitrogen at 

 depths of 7 and 14 feet than at the surface. The organic matter of 

 soils is of two kinds — the humous portion and the bituminous ; the 

 latter being regarded as belonging to the original deposit from which 

 the soil is derived. Analyses of soils and subsoils are given to 

 illustrate this point. Further light on this subject is derived from 

 the analysis of a series of specimens from the following deposits, 



