Vol. XXviii.] PALAEONTOLOGY OF LANCASHIRE COAL MEASURES. 409 



It is by no means improbable that this was due to more 

 staple geographical conditions in the first case. 



Geographically, the various life forms seem to have been 

 most numerous in numbers and species along the north- 

 eastern and northern portions of the Lancashire coal field, 

 more especially in the latter. Over the rest of the area life 

 forms are fairly evenly distributed. 



In conclusion, the writer's endeavour has been to prove 

 the horizon and geographical occurrence of each species as 

 far as possible by reference to known specimens, and thus 

 afford data for a better knowledge of the palaeontology, and 

 also a starting point for future work. 



The writer must also record his gratitude to Prof. W. 

 Boyd Dawkins and Dr. W. E. Hoyle, of the Manchester 

 Museum, for the facilities given to him. whilst a member of 

 the staff, and for continued interest and help. 



