Alfred Bell — Fossils of East Anglian Boxstones. 407 



after treatment with a bar-magnet, a grain or two of brown 

 tourmaline was also found. The specific gravity of both specimens 

 is 2*63, the same figure as that for the granophyre. 



Mr. Hemingway states that the rock is very similar to the white 

 felsite interbedded in the Drygill shales to the north of Brandy Gill. 



Geological Age. 



It may be of interest to draw attention here to the recent work of 

 Mr. J. F. N". Green on the age of the Carrock Fell complex. 1 It is 

 well known that the complex is of later date than the Borrowdale 

 volcanic series. An upper limit is fixed by Mr. Green's discovery of 

 granophyre fragments in the Watch Hill Beds. These consist of 

 shales and polygenetic grits which form a series of patches lying at 

 various horizons on the Skiddaw Slates between Cockermouth 

 ( Watch Hill) and Great Sea Fell. 2 Only one pebble of granophyre 

 was found at Watch Hill, but in the eastern exposures (i.e. in those 

 near to Carrock Fell) the rock was found to be invariably present in 

 the coarser bands of the series. Mr. Green shows that the Watch 

 Hill Beds are younger than the Borrowdale Series and older than the 

 Devonian earth-movements, and for these and other reasons he 

 correlates them with the Coniston Limestone Series. Consequently 

 he considers the igneous rocks of Carrock Fell to be pre-Bala. 

 Mr. Green concludes: "The Borrowdale Series is ascribed to the 

 Middle Llanvirn . . . The Eskdale granite, Buttermere granophyre, 

 St. John's granite-porphyry, and Carrick Fell complex all belong to 

 the suite, being intruded before the solfataric stage, but at a late 

 period of the episode." 



Y. — The Fossils of the East Anglian Sub-Crag Boxstones. 

 By Alfred Bell. 



IjST the opening article of the Geological Magazine (Vol. I, p. 5, 

 1864) Mr. J. W. Salter remarks: " An obscure but novel group 

 of organic remains comes to light in some well-worked district for 

 which we have as yet no fixed geological place," and this description 

 may well apply to the fauna dealt with in the following pages. 



Usually considered by geological writers as being derived from 

 sources outside the East Anglian area, very little attention has been 

 paid to it, its environment, or to its Continental affinities. The 

 fossils hereafter referred to occur in a sandstone matrix 3 more or 

 less consolidated, the relics of a former stratum afterwards broken 

 up, and now found distributed in places beneath the overlying 

 Pliocene deposits, between Walton-on-the-Naze and Hollesley on the 

 coast and inland to about Ipswich. 



1 " The Age of the Chief Intrusions of the Lake District " : Proc. Geol. 

 Assoc, xxviii, pp. 17-25, 1917. 



2 Ibid., plate ii. 



3 An interesting and important paper dealing with the petrology of the 

 Suffolk " Boxstones " (Crag), by Dr. P. G. H. Boswell, D.I.C., F.G.S. (now 

 Professor of Geology in the University of Liverpool), appeared in the 

 Geological Magazine for June, 1915 (pp. 250-9, Plate X, and Figs. 1-3) 

 and may be consulted with advantage by readers of the present paper. 



