102 SCIENCE PROGRESS. 



sometimes of animal origin is clear from the vast quantity 

 of cyprids which make up some of the shales. Large 

 plants are rare in these shales, but ferns are abundant. 



In conclusion we have to deal with a very important 

 group of papers treating of the distribution of coal under 

 newer rocks, a subject that has received an unusual amount 

 of attention of recent years. The first of these papers on 

 the Forest of Wyre coal-field (14) is of somewhat local in- 

 terest. It deals with the question of the distribution of the 

 lower coal measures beneath the upper measures of that 

 field. The author insists upon the value of the Spirorbis 

 limestone, occurring in the upper coal measures, as a datum 

 line. These upper coal measures, with "stinking" or "sul- 

 phur " coal, owing to the existence of the Symon Fault in this 

 basin, rest unconformably upon the lower measures, with 

 "sweet" coal resembling those of Coalbrookdale. He be- 

 lieves that the sweet coals only occur in the twelve thousand 

 acres around Kinlet Knowle, in the Forest of Wyre coal- 

 field, and are absent elsewhere, owing to the " Symon 

 Fault". This "fault" he supposes to run in the direction 

 of Shatterford, and maintains that on that account the 

 " sweet " coals are absent there. The paper is illustrated 

 by a map and sections. The next paper (15) treats of the 

 important subject of the extension of the Yorkshire coal- 

 field beneath the newer rocks to the east (15). It is illus- 

 trated with a map showing the outcrops of the Ganister, 

 Silkstone and Barnsley coals in the Yorkshire, Derbyshire 

 and Notts coal-field, and with sections. The author discusses 

 the shape of the whole basin. "It would seem that the centre 

 of the trough or coal-basin runs in a line from north-west 

 to south-east, starting at the north-western outcrop of the 

 coal measures, say at Denholme, about half-way between 

 Halifax and Keighley, and proceeding south-west through 

 Cleckheaton, Batley Carr, Sandal Castle (about two miles 

 south of Wakefield), South Kirby and Doncaster. If this 

 line were continued it would pass through Gainsborough to 

 a point about seven miles north of Lincoln, and farther east 

 to a point three or four miles south of Horncastle." He 

 suggests the possibility of the easterly dip on the north-east 



