216 The Rev. W. Con ybeare on the North East of Ireland. 



5. The sandstone district, of which the lower beds are associated 

 with the coal, and the upper with gypsum. The collieries are distin- 

 guished by black circles. 



6. The zone formed by the basset of the chalk round the escarp- 

 ments of the mountain groupe, which forms our third system. It 

 was not possible to insert the lias and greensand intervening between 

 the sandstone and chalk ; but their localities are fully indicated in the 

 paper and in the sections. 



7. The great district of floetz trap. 



The smaller map, PI. 9, exhibits a general outline of the opposite 

 points of Scotland and Ireland, intended to shew the connection be- 

 tween the principal formations in each country, as pointed out in the 

 Introduction. The colours represent. — 1. Granite. 2. The mica 

 slate district of the Grampians, and the northern chain in Ireland. 3. 

 The transition district of the Lead hills in Scotland, and of Down In 

 Ireland. 4. The secondary rocks associated In the coal district. 

 5. The floetz trap districts. 



