628 



UEPoiiT — 1886. 



glomerate, and a smaller quantity of intensely hard pieces of black siliceous rock. 

 All the ahove-mentioned fragments are few in number compared with the quartzite 

 pebbles. The pebbles vary in size from half an inch to over a foot in diameter. 

 The fossils contained in the drift-pebbles are exceedingly rare, especially perfect 

 specimens ; about one fossiliferous pebble occurs in two or three thousand stones, 

 and this perhaps contains fragments only. 



Perfect fossils are seldom met with ; when a complete specimen is found it is 

 generally in a good state of preservation. The pebbles contain brachiopods, 

 lamellibranchs, cephalopods, gasteropods, annelids, plants, crinoidal stems, and 

 fragments of trilobites of different species. 



5. Surface Subsidence caused hy Lateral Goal Mining. 

 By Professor W. E. Benton, Assoc. B.8.M. 



The author showed that a large amount of coal is annually sacrificed in British 

 coal-mining for the lateral support of neighbouring and disinterested surface pro- 

 prietaries : and pointed out the results of this sacrifice, together with the considera- 

 tions which should govern the extent of this support. 



6. Exhibition of some Organisms met with in the Glay-Ironstone Nodules 

 of the Coal-measures in the neighbourhood of Dudley. By H. WoOD- 

 WAKD, LL.D., F.B.S., and R. Etheridge, F.B.S. 



7. Notes on the Discovery of a large Fossil Tree in the Lower Coal-measures 

 at Clayton, near Bradford. By S. A. Adamson, F.G.S. 



The author described the discovery of a huge Sigillarian stump, with eight 

 forked Stigmarian roots attached, at Murgatroyd's Fall Top Quarry, Clayton, near 

 Bradford. It was discovered about 12 feet below the surface in the measures 

 between the Better Bed Coal and the Elland Flagstone. The stump of the tree 

 was embedded in soft sandy shale, locally termed ' yellow loam,' the roots resting 

 on a bed of soft blue shale, which some of them penetrate. The following 

 ■dimensions of the fossil were given :— 



Height of stump . . • . . . . . 3 ft. 9 in. 



Diameter of stump (longest axis) 4 ft. 6 in. 



„ (at right angles to longest axis) . 3 ft. 10 in. 



The following figures give details of the roots : — 



Root 



No. 1 



,, 2 



„ 3 



,, 4 



„ 5 



,, 6 



,, 7 



„ 8 



Dist.ance from 

 stump to bifur- 

 cation of roots 



4 ft. 



ft. 

 ft. 

 ft. 

 ft. 

 ft. 

 ft. 

 ft. 



Gin. 

 6 in. 



Distimce from point of bifur- 

 cation to present termination 

 of root 



Left fork 

 13 ft. 

 6 ft. 

 ft. 

 ft. 

 ft. 

 ft. 

 ft. 

 ft. 



6 in. 



6 in. 



6 in. 



Greatest 

 length of root 



17 ft. 

 12 ft. 

 12 ft. 

 8 ft. 6 in. 

 10 ft. 

 10 ft. 



10 ft. 6 in. 

 16 ft. 6 in. 



The diameter of the visible area covered by the ramifications of the roots is, 

 from N. to S. 29 feet 6 inches, and from E. to W, 28 feet; giving a superficial 

 area exposed of 826 feet. 



