Britten : Notes on Birds of tJie Eden Valley. 



It will be observed that I have drawn my boundary line 

 about six miles from the axis of the anticline, that was to allow 

 room for a belt of Lower Carboniferous rocks, without any 

 covering- of Coal Measures on the crown of the fold as we find 

 to be the case with the Pennine Chain. The caution may be 

 superfluous for the Lincolnshire anticline is neither very broad 

 nor very hig-h. 



T/2e SoiitJiern Bonndaiy. — I have already mentioned the 

 g-eneral conclusions at which I have arrived regarding- the 

 position of the southern edge of the coalfield. I have sought 

 in vain for signs of a fold or other structural feature which 

 might indicate a limit to the coalfield in a southerly or south- 

 easterly direction, anywhere north of the great depression of the 

 Fens. South of that region, however, it is well known that 

 a great mass of hard and ancient rocks occupies a great area 

 under the London Basin. It has been proved in several deep 

 borings, of which the nearest to the Fen Country of Cambridge- 

 shire are at Ware in Hertfordshire, 38 miles from King's 

 Repton, where I have drawn the boundary, and Culford, near 

 Bury St. Edmunds, only eight miles from the beginning of the 

 Fens at Mildenhall. 



As in both of these cases rocks much older than the Carboni- 

 ferous were encountered immediately underlying the Cretaceous 

 rocks, it is certain that the coalfield cannot extend so far as 

 these two sites. Some justification could be given for drawing 

 the boundary line very near the actual edge of the Fens, but 

 I have preferred to suggest a boundary well within that limit. 



It is to be expected that a considerable and rather rapid rise 

 of the Coal Measures will be discovered near the margin of the 

 field. 



[Detailed evidence is presented in a series of appendices.] 



NOTES ON BIRDS OF THE EDEN VALLEY. 



HARRY BRITTEN. 



Snlkfld Dykes.. 



: (Continued from p. 208.) 



CcCKOO. Abundant as a summer visitant to the Eden Valley. 



White or Barn Owl. This beautiful owl is not as common as foi-nierly, 



but it still breeds in a few favourite spots in the Eden Vallo}-. 

 LoNG-EARED OwL. This is a common resident in the Eden Valley ; in iV.ct, 



it is the most numerous species of owl in this district at the present 



1905 Aug-ust I. 



