492 Scientific Proceedings, Royal Dublin Society. 
Permian up into the Jurassic. In the following table the first 
column gives the maximum thicknesses of the rocks of Ireland, 
and the second and third of England and the Continent. For 
the classification of the English and foreign rocks I am indebted 
to Professor Lebour, of the Durham University. 
Trish. English. Continental. 
4, JURASSIC. Belgium. 
Lias. Oolite, 2,500ft. (J.B. Jordan.) Upper Lias, 50 to 100 ft. 
Lias, 1,400 ft. x (Dewalque.) 
Lr. Lias, 600 to 900 ft. (Lyell.) Middle ,, 400 to 460 ft. 
(Dewalque. ) 
Lower ,, 300 to 450 ft. 
(Dewalque. ) 
France. 
Liasien beds, 500 ft. 
(D’Orbigny.) 
Sinémurien beds, 1,000 ft. 
(D’Orbigny.) 
3, RWATIC. 
Maximum, 100 ft. Maximum, 50ft. (J.B. Jordan.) Belgium, thin and variable. 
(Dewalque. ) 
Austrian Alps, 50 ft. (Giimbel.) 
Keessen beds, 50 ft. (E. Suess.) 
2. TRIASSIC. 
Keuper, 1,100 ft. Keuper, 3,400 ft. max. Hartz, Bunter, 1,000 ft. 
Bunter, 900. (J. B. Jordan.) (V. Meyer.) 
Bunter, 1,500 ft. max. Austrian Alps, Bunter, 2,800 
(J. B. Jordan.) to 3,200 feet. (Giimbel.) 
Keuper, 1,500 ft. max. Dachstein beds, 2,000 ft. 
(Ramsay.) (E. Suess.) 
Kemper, 1,000 to 1,700 ft. Hallstadt beds, 800 to 1,000 ft. 
Bunter, 600 ft. (E. Suess.) 
Cheshire and Lancashire. Guttenstein beds, 150 ft. 
(Ormerod.) (E. Suess.) 
Werfen beds, very variable. 
(E. Suess.) 
Wiirtemberg, Keuper, 1,000 ft. 
(Alberti.) 
1. PERMIAN. 
Perhaps 100 ft. Upper Permian, 1,500 ft. 
(J. B. Jordan.) 
Lower ,, 3,000 ft. 
(J. B. Jordan.) 
The Irish Permians cannot exceed 100 feet in thickness in any 
place where they are seen. According to King and Baily their 
fossils prove them to be equivalent to the Durham and Yorkshire 
rocks, that is, the “Middle Permian” of Lyell. Yet these Irish 
rocks are the base of the Triassic, and merge so gradually into 
them that they could not have been separated from them but for 
their fossils. In the valley of the Lagan (cos. Down and Antrim) 
the rocks lying upon them are said to be the representatives of 
