116 REPORT 1871. 



instead of 154, or 7 per cent. less. A similar, but generally less correction, 

 may be required for other stations. The figures in Table V. must not there- 

 fore be considered as showing the mean fall at the several stations, but only 

 as approximations generally pretty close. The data in our possession, if cor- 

 rected in accordance with the method explained, would afford more accurate 

 results, but the investigation is altogether beyond our present resources. 



Large tracts of Ireland, and even of Scotland, are still without observers ; 

 much has recently been done to remedy these deficiencies, but there are still 

 many localities where observations are very much wanted ; we shall gladly 

 receive any off'ers of assistance from those who have residences or property in 

 those parts, and our Secretary wUl readUy advise them as to instruments. 



Third Report on the British Fossil Corals. By P. Martin Duncan^ 

 F.R.S.f F.G.S., Professor of Geology in King's College, London. 



Introduction. — There can be no doubt that the palaeontology of the Madrc- 

 poraria of the Palaeozoic strata is in a condition of profound confusion. 

 When these Reports were commenced, the veiy excellent descriptions and 

 classification of the Palaeozoic Corals by MM. Milne-Edwards and Jules Haime, 

 strengthened by those of M. de Eromentel, appeared to have satisfied pa- 

 heontologists, and they were received and adopted without much demur. 

 But during the last three or four years a series of more or less important 

 attacks has been made upon the views of those distinguished authors ; 

 consequently opinions respecting many important matters in the palaeontology 

 of the Palaeozoic corals are in a very unsatisfactory state. 



L. Agassiz, A. Agassiz, and now Count Pourtales would remove the Ta- 

 bulata from the list of Madreporaria. Mr. Kent and I doubt the propriety 

 of establishing the Tabulata as a group. Count Keyserling demurred years 

 since at receiving the long se])taless Tubulata amongst the Madreporaria, 

 and, after due examination, I agree with him in relegating them to the Al- 

 cyonaria. 



Working amongst the Rugosa, I have shown that they do not invariably 

 characterize Palaeozoic strata, for some of the types have persisted, and no 

 reasonable doubt cau be entertained concerning the descent of the Jurassic 

 Coral-fauna fro'n the Palaeozoic. 



The genus Palceocyclns has been shown not to belong to the Fungidac, 

 but to the Cyathophyllidae. Genera with the hexameral arrangement of 

 septa have been found in Carboniferous and Devonian strata. 



Lindstrom's interesting researches respecting the operculated condition of 

 some Palajozoic corals require most careful study and much following up, 

 and the assertion of L. Agassiz respecting the hydroid relationship of those 

 Eugosa which have tabulae demands further inquiry *. 



Ludwig, of Darmstadt, has added to the confusion by not acknowledging 

 the received classification in the least ; and in his able enthusiasm (anti- 



* G-. Lindstrcim, pamphlet translated by M. Lindstrcim from the original Swedish, 

 ' Geological Magazine,' 1866, p. 356. He notices tliat Guettard first described an oper- 

 culum in a rugose coral, and that then Steenstrup saw one in a Cyathophyllum mUratum. 

 Lindstrom produces evidence respecting the genera Gonlophylhim, Calceola, Zaphrcntis, 

 Hallia, and Favosites (see also p. 406 et seq.). 



