﻿546 THE MARINE BANDS IN THE [Aug. 1905, 



Figs. 6 & 7. Orthoceras aff. asciculare. Same locality. (See p. 542.) 

 Fig. 8. Orthoceras, sp. Same locality. (See p. 542.) 

 Figs. 9 & 9 a. Euphemus cf. Urei. x 3. Same locality. (See p. 538.) 

 Fig. 10. Spirorbis, sp. X 3. Same locality. (See p. 502.) 



Discussion. 



The President said that he welcomed the paper, as adding a 

 number of new facts to those which we already possessed. The 

 paper was an example of those which (themselves concerned with 

 pure science) were nevertheless likely to be of much economic value. 

 He was glad to hear the Authors bring forward what appeared to be 

 conclusive evidence that Naiadites, Carbonicola, and Anthracomya 

 did not occur in association with the marine forms. 



Mr. Walcot Gibson congratulated the Authors on an important 

 piece of work which had a practical bearing, especially on the 

 question of determining one's position in the Coal-Measure sequence 

 in concealed areas. He did not think that the presence of Lingula 

 alone was a safe index of position in the absence of other data. He 

 would like to ask Mr. Stobbs in what sense he used the term ' true 

 Coal-Measures.' 



Dr. Teall associated himself fully with the complimentary 

 remarks which had been made on the paper, but said that he had 

 not quite gathered what were the main features upon which the 

 Authors relied for the identification of particular marine bands. 

 He enquired whether they relied on the limitation of the range 

 of some particular forms, or on the general association. 



Prof. P. F. Kendall desired to associate himself with the ex- 

 pression of approval which had fallen from previous speakers. The 

 Authors were engaged upon a piece of work, the progress of which 

 he and other geologists in Yorkshire were watching with the keenest 

 interest and gratification, and he expressed the hope that they would 

 extend their researches to the coalfields on the eastern side of the 

 Pennine Chain. 



He remarked that the arguments which had been employed to 

 prove that there were two molluscan faunas in the Coal-Measures, 

 one marine and the other containing Aniliracosia of freshwater 

 habitat, were employed by Green in his monumental memoir on 

 the Geology of the Yorkshire Coalfield. One apparent exception, to 

 the rule that marine fossils never occurred in association with the 

 Anthracosia-grou^ of shells, was recorded in the case of the Thin 

 Coal, which lies almost immediately upon the Rough Hock; but 

 further research in more accessible sections showed that the Anihra- 

 cosia-'Ba.Jid formed the true roof of the seam, and was covered in its 

 turn by shale containing marine organisms. In Yorkshire, marine 

 bands occurred in nearly all the larger shale-beds of the Millstone 

 Grit, from the top of the Kinderscout Grit to the shale immediately 

 underlying the Rough Rock ; but in the Coal-Measures only two or 

 three marine horizons had been recognized : one of these was just above 

 the Thin Coal, and another formed the roof of the Gannister Coal. 



Regarding the correlation of the coal-seams upon opposite sides 

 of the Pennine Chain, it should be borne in mind that the recog- 

 nition of the identity of the Silkstone Seam of Yorkshire with the 



