148 H. Cuipin — Marine Beds in Coal-measures, Yorlcshire. 



Especially close is the comparison between the two New Zealand 

 faunas and those of the beds 2 and 3 of Ruedemann in his Deep Kill 

 section (Graptolites of New York, part 1, 1904, pp. 504-507). 

 Some of the new species described by Kuedemann in this great work, 

 which have not hitherto been recognised in other parts of the world, 

 are to be found in Mr. Isaacson's collection. The fauna of the band 

 (a) corresponds to that of bed 2, and the fauna of {h) to that of 

 bed 3, and this fact gives additional support to the assumption that in 

 the Aorere Series of New Zetdand two graptolitiferous zones are 

 represented. 



With Great Britain the comparison, though close, is not so striking. 

 This is mainly due to the fact that in Britain the rocks at this horizon 

 are not so rich in species as they are in America. So far, however, as 

 the range of the species which are common to both Great Britain and 

 New Zealand is concerned, it is clear that the fauna («) corresponds to 

 that of the zone of DidymograpUis extensus, and the fauna of {b) to that 

 of the zone of Didijmograptus Idrundo. In Wales the Dtdymofiraptus 

 hirundo zone is extremely poor in species, and the zone fossil has not 

 yet been recognised from New Zealand. In Britain Didymograptus 

 namis makes its first appearance in this zone, though it is very rare ; 

 probably, therefore, the fauna of («) corresponds to that of the 

 highest beds of the J), hirundo zone and to that of the base of 

 the overlying zone of D. hifidus. 



In the Lake District the New Zealand faunas find their repre- 

 sentatives in the Middle Skiddaw Slates, and probably also in the 

 lowest beds of the EUergills. 



Mr. Isaacson's present discovery shows indisputably that the 

 association of forms in the part of New Zealand which he has 

 investigated is practically the same as that in the Northern Hemi- 

 sphere ; and it may be anticipated that further work will result in 

 proving that the zonal succession of graptolites so well established in 

 the Northern Hemisphere prevails in New Zealand also. 



II. — Makine Beds in the Yokkshire Coal-measukes above the 



Baensley Coal. 



By H. CuLPiN. 



IN Green's " Geology of the Yorkshire Coalfield " (Mem. Geol. Surv., 

 1878, p. 471) reference was made to the occurrence below the 

 Ackworth rock of a band of black shale, which it was said " contains 

 Aviculopecten in plenty, and shows that incursions of the sea con- 

 tinued to occur even up to these comparatively late portions of the 

 Coal Measure period." 



A recent sinking for coal at Brodsworth, about four miles north- 

 west of Doncaster, gave an opportunity, which the Colliery Manage- 

 ment kindly facilitated, for a search for the above and other marine 

 beds above the Barnsley Coal, with the result that four such beds 

 have been noted there, one of which has markedly distinctive 

 lithological and faunal characters. 



Taking the beds in descending order, the first was found in some 

 32 feet of 'blue bind,' the base of which was 106 J feet below the 



