308 THE CANADIAN NATURALIST. [Sept. 



thic breccia, 210 to 315 feet thick. The line of separation 

 between the breccia beds and the beds of boulder trap is re- 

 markably sudden and no gradation of character occurs between 

 them. The breccia is worked for hard felspar used for pottery 

 purposes, and contains small nests of steatite. The bouldered 

 condition of the felstone beds was considered due to their partial 

 breaking up on being erupted under water, the soft matrix of 

 felspathic tuff being the portion more intimately divided, and the 

 compact boulders, fragments that had resisted disintegration. 

 The sudden alternation in Middieton Hill of eruptive beds of 

 very dissimilar character was noticed ; they seem all to have been 

 emitted in immediate succession, as although overlain and under- 

 lain by sedimentary deposits. There is no evidence of inter- 

 stratification of sedimentary beds. The author, in conclusion, 

 pointed out the close geographical association with these bedded 

 traps, of the much later porphyritic greenstone of the Breidden 

 Hills, which it was suggested might have been emitted from the 

 same points of eruption ; and the local association of the intru- 

 sive greenstones with the lower silurian interbedded felstones was 

 noticed as being very general in N. Wales. 



Professor Dawkins said he had by accident very recently ex- 

 plored the same district as had been described by Mr. Maw, and 

 he could corroborate his statements. There could be no doubt 

 that the boulder track was due to the attrition of waves. He 

 asked for some further information as to the appearance of the 

 great mass of freestone after the close of the triassic era. 



Mr. Maw replied to Mr. Dawkins by citing the authority of 

 Sir R. Murchison. 



ZOOLOGY AND BOTAN"T. 



COLOUR IN BIRDS. 



(^From the President's Address.) 



The Turaco, or plantain-eater, of the Cape of Good Hope is 

 celebrated for its beautiful plumage. A portion of the wings is 

 of a fine red colour. This red colouring matter has been investi- 

 gated by Professor Church, who finds it to contain nearly six per 

 cent, of copper, which cannot be distinguished by the ordinary 

 tests nor removed from the colouring matter without distroying 

 it. The colouring' matter is in fact a natural organic compound 

 of which copper is one of the essential constituents. Traces of 



