IJ4 tKOOEEDlNGS OF THE GEOLOGICAL SOCIETY* [May 1 894, 



Sphaeroidea and Pruaoidea. Without distinctly stating the age, 

 he went so far as to remark that, in their general condition of 

 preservation, the radiolaria in this Cornish chert strongly resemble 

 those in the Ordovician chert of Scotland. "Messrs. Fox and Teall 

 regard Mullion Island as belonging to the sedimentary series which, 

 on the mainland, is faulted against the Lizard rocks, although they 

 failed to find the particular beds of the island in any part of the 

 immediate neighbourhood. 



To judge from the foregoing extracts it cannot be doubted that 

 considerable progress has of late been made towards a recognition 

 of the true character of the Lizard rocks, which, for the extent of 

 territory they occupy, are perhaps without equal in point of interest 

 throughout the British Isles. Prof. Bonney may be said to have re- 

 discovered these rocks about seventeen years ago, and his recognition 

 of the true origin of the serpentine laid the foundation for the correct 

 diagnosis of the entire peninsula, whilst it put an end to a considerable 

 amount of crude speculation. Another phase in the history of the 

 Lizard dates from the publication of Mr. Teall's instructive paper on 

 the Origin of certain Banded Gneisses, 1 wherein he contended that a 

 series of rocks, hitherto regarded as sedimentary, are really of igneous 

 origin, and that the parallel structure which characterizes many of 

 them has nothing to do with stratification in the ordinary sense of 

 the word, but is a consequence of the deformation to which the 

 original rock-masses have been subjected. 



Practically there is now no dispute, one may say, as to the cha- 

 racter of these banded gneisses, which present an appearance so 

 curiously imitative of sedimentation ; and although there may be a 

 slight reserve in some quarters as to the possibly pyroclastic origin 

 of a portion of the hornblende-schist, the rocks of the Lizard 

 peninsula, as a whole, are regarded by all as truly igneous. 

 Amongst the more important issues which yet remain for decision 

 is the question as to how far the peculiar structure of the banded 

 gneisses is due to deformation, or to some congenital peculiarity as 

 suggested by General M e Mahon. The next question seems likely to 

 prove a thorny one, viz. the determination of the order of succession 

 in the several igneous masses. This latter point is really not one of 

 prime importance, since practically the Lizard rocks, for the most 

 part, are of one age, and constitute an igneous- — possibly a plutonic 

 — complex, portions of which have been folded, and the whole thrown 

 into such confusion that the story told by one section may perhaps 



1 Geol. Mag. 1887, p. 484. 



