Vol. XXviii.] PALiEONTOLOGY OF LANCASHIllR COAL MEASURES. 579 



wherever possible, giving a number to each level wliere 

 fossils occur, and placing the same number upon the fossils 

 obtained at that horizon. The collector ought also to take 

 especial care to get fossils out with a fair amount of the 

 matrix attached, so that no possible doubt can afterwards be 

 raised as to the character of the stratum. The association of 

 the matrix with the fossil will enable the palaeontologist 

 to determine with more accuracy the circumstances and 

 conditions in which the particular fossil lived or was 

 entombed. The determination as to whether a fossil was of 

 freshwater, estuarine, or marine habit is helped considerably 

 by an examination of the rock in which it occurs, and only 

 in this way can it be settled whether a fossil is derived from 

 older rocks, drifted from another area, or actually liv6d in 

 situ. 



The best example I know of what may be done by 

 careful collecting, and accurate measurement during sinking 

 operations, is the paper and table of strata given by the late 

 George Wild in Vol. XVIII. of the Society's Transactions. 

 A perusal of that paper will show that the occurrence of 

 fossils has been carefully noted, and most important of all, 

 the depth below, or height above some well-known seam or 

 datum line. That excellent paper emphasises one feature 

 in the description of a section which creates considerable 

 difficulties when correlation of seams is attempted. I allude 

 to the varied terms used throughout the coalfield to describe 

 the various strata met with between the seams ; " blue metal," 

 "strong blue metal," "rag" or "gritty metal," "shale," 

 "bing," &c., are all terms capable of several meanings, 

 according to the district in which they are used. If a 

 standard series of specimens of the strata intervening between 

 coal seams could be secured, and a distinctive descriptive 

 title applied to each, it would almost certainly help in the 

 correlation of strata, and prove a more effective guide to 



