76 SCIENCE PROGRESS 



round a definite centre, with minor variations, and that they 

 do not depend on the main tectonic movements which have 

 determined the present lie of the beds. It thus comes about 

 that in some places in that part of the coalfield where the 

 measures are thickest the seams are bituminous and not anthra- 

 citic, as they should be were the anthracitisation simply a 

 tectonic result, changing to anthracite coals which had been 

 originally bituminous. Dr. Strahan finds that " serious objec- 

 tions present themselves " to the three explanations by previous 

 workers of the change in the character of the same seam in 

 different parts of the Welsh coalfield. But then suddenly, 

 in the most disappointing way, the work comes to an end ! 

 The paper closes just when, to my palseontological mind, it had 

 illuminated one side of the problem and prepared the ground 

 for a detailed microscopic examination of the coals. The 

 abrupt conclusion " that the differences between the anthracitic 

 and bituminous coals in South Wales are mainly due to original 

 differences in composition " is discussed for a few pages, but 

 no evidence whatever of a positive, palseontological nature is 

 brought forward in its support. Until much detailed micro- 

 scopic work has been done on the subject it is impossible to 

 speak dogmatically, but I may remark that the general dis- 

 tribution of the Welsh anthracites, coupled with what is 

 known of the American and other anthracites, makes it very 

 difficult for a palseobotanist to accept the conclusions of this 

 paper in the simple way the}r stand. The interpretation of the 

 meaning of ash analyses in the various kinds of coal can con- 

 ceivably lead in a very different direction from that taken 

 in the present paper, and is an entrancing theme, too extensive 

 to be dealt with here. 



The Russian paper differs from the two preceding mono- 

 graphs in being less a consideration of coals in general than a 

 description of a single kind of coal, and this of a type new to 

 science. The description is essentially palaeontological and is 

 accompanied by some superb micro-photographs of the new 

 fungi and other micro-organisms found in between the layers 

 of the larger alga which forms the coal. This alga is described 

 as so closely resembling the recent Himanthalia that the fossil, 

 coal-forming species, is named Himanthaliopsis Sniatkovi sp. 

 nov. This new coal is unfortunately represented only by 

 hand specimens, and has not been found in situ, so that many 



