OF THE CARBONIFEROUS SERIES. 651 



classification as a whole, but thought that such hard separate 

 groups as appeared to be indicated could not be sustained. In 

 Shropshire we have at the top of the Coal-measures the Sjrirorbis 

 Limestone, then beds with various marine fossils, and below these 

 deposits with Anthracosia?. In Belgium the Coal-measures are also 

 associated with beds containing BelUrophon and other marine forms. 

 He considered the character of the Carboniferous series to be depen- 

 dent on conditions of depth in the different areas. 



Mr. Etheridge thought that previous speakers had been rather 

 hard on Prof. Hull, seeing that the sharp lines objected to are pre- 

 cisely those which we have been long working on, and the author 

 had merely attempted to correlate certain beds. The author's lists 

 of fossils seemed to him to be of great use as evidence of very sig- 

 nificant changes. Mr. Etheridge maintained that in the correlation 

 of these, as of other deposits, palaeontological as well as physical 

 evidence must be taken into consideration. It was difficult to 

 understand how such a flora as that of the Coal-measures came to 

 be associated with a marine fauna. Mr. Hull's groups were not 

 new ; but the grouping was important, and Mr. Etheridge was dis- 

 posed to agree with him in his correlations. 



Mr. Warentgton W. Smyth referred to the work done in connexion 

 with these questions more than thirty years ago by Mr. Binney, and 

 expressed a hope that due credit was given to that gentleman in 

 the paper. It seemed to him that the author had set out by esta- 

 blishing the homotaxis in this country, but that he had then jumped 

 to a cod elusion about the deposits in Scotland. He inquired if there 

 was evidence of the Gannister beds between those generally so called 

 in England and those in Scotland, as, for example, in Durham. 



Prof. Morris agreed with Prof. Dawkins as to the difficulty of 

 recognizing a break at the Gannister beds, the distribution of which 

 was very interesting ; but they differ in their characters somewhat in 

 their E. and W. range to Wales, as compared with their trend from 

 S. to N. towards Scotland. Some of the marine forms in these 

 rocks are species continued from the old Carboniferous sea. He said 

 that Anthracosia was certainly not a Unio. In Shropshire there are 

 intercalated marine beds, and with these the same Anthracosia. In 

 Scotland the horizons are not so distinct. 



The Author, in reply, said that some of the points raised b}* the 

 speakers were already met in his paper. He stated that he had on 

 principle rejected both fish and plants as furnishing data for classi- 

 fication : the fish were Ganoids, and therefore probably migratory. 

 Hence we are compelled to fall back on the Mollusca. Throughout 

 the investigation Anthracosia had been his bane, since it occurs 

 sometimes with marine and sometimes with freshwater companions. 

 As regards the term " Yoredale series," he used it in this paper in 

 the sense adopted by the Geological Survey in the districts of Derby- 

 shire, Lancashire, and Yorkshire. It seemed to him that sufficient 

 importance had not been given by the speakers to the palaeontological 

 break above the Gannister beds ; out of 75 species of marine genera 

 below this line not more than 6 pass upwards. 



