630 ME. H. BOLTON, P.E.S.E., ON [June, 1904. 



Burnley District. 



The Middle Measures of the Burnley district have yielded, 

 if we eliminate doubtful genera such as ''Modiola" and 

 '' Orthonota/' no less than 27 genera and 38 species belong- 

 ing to the following groups : — Pelecypoda, four genera, 

 eight species. Crustacea, one genus and one species. 

 Pisces 20 genera and 29 species. Amphibia one genus. 



The dominant forms are fishes, which come in at the 

 very bottom of the Coal Measures, no less than 16 species 

 occurring in the roof of the Arley Mine, and 15 in the roof 

 of the Californian or Thin Bed. Cephalopoda and 

 Brachiopoda appear to be absent, whilst Crustacea and 

 Pelecypoda are less abundant in numbers as well as species 

 than in the Lower Coal Measures. 



Most of the genera and species of fossils in the Burnley 

 district come from the black shale roofs over the lower seams, 

 the Californian or Thin Bed being most prolific. 



The Bastard Cannel at FuUedge Colliery, and the Lower 

 Yard Bed show a remarkable falling off, only one species of 

 moUusca (C. robusta) being recorded from both if we except 

 the form named by the late George Wild as ^^Orthonota." 

 Mollusca and Crustacea are characteristic of the Low Bottom 

 Bed. 



Bolton District. 



An examination of the following table shows a marked 

 difference to what we find in the Burnley area. There is a 

 greater molluscan development, and a more general distri- 

 bution of fossils through the whole Coal Measure series. 

 Only in the case of the Pendleton or Worsley Four Feet 

 Mine do we find a marked occurrence of fish remains, and 

 these do not equal in genera and species what are found in 

 the Burnley area. 



