JL. Bell — Succession of the Later Tertiaries in Gt. Britain. 73 



The fauna of the "Mud Deposit" at Selsey, unfortunately so 

 seldom visible, is exceedingly rich, as is well known, in shells of this 

 age and character. The gravel beneath it is rich in land shells, but 

 so rarely viewed as to be almost unknown. As described elsewhere 

 by myself, I have taken from the mud bed 140 species of shells : 

 of these about 30 do not come north of the Channel Islands or the 

 north of Spain, eight being exclusively Mediterranean forms. 



This extension northwards of southern types is visible very 

 notably in the Middle Sands of the North- West of England and 

 Wales, in the Shropshire and Severn gravels, etc. Undoubtedly all 

 these are not of one age, but belong to various periods of the great 

 submergence, as already indicated for the Scottish fauna. The given 

 fauna from these beds is rich, almost too rich, for there is a shrewd 

 suspicion that all the species quoted are not genuinely native, especially 

 when obtained from the workmen. Many quarrymen unhesitatingly 

 bring recent Naticas and other species, some with Confervas on them, 

 as the product of the soil. Mr. Darbishire, Mr. Maw, and myself 

 in a small way have found this, even to the offering of the pearl 

 oyster and other West Indian species. 



Apart from this, the beds exhibit Venus CMone and other southern 

 shells (and in Ireland Woodia digitaria) at higher latitudes than 

 those they are now found living in. The finest and most instructive 

 series, because almost every specimen has been obtained under 

 the supervision of the owners of the gravel pit from whence 

 they were exhumed, and preserved with great care, is that in the 

 possession of the Misses ffarrington, of Worden, Lancashire, in 

 which every species known to the N.W. gravels is contained with 

 many others confined to this pit alone. When, by the kindness of 

 the Misses ffarrington, I had the pleasure of working out the entire 

 series, I found that from 130 to 140 species were represented, and it 

 was not only in the number of southern species, but the southern 

 exuberance of form and sculpture put on by such shells as Murex 

 erinaceus, still with us, that testified to the extension northward, and 

 the consequent indication of the southern climate that these showed. 



Western currents were at times probably prevalent, since the find- 

 ing of a West Indian Olive (0. jaspidea apparently from Sti-ickland's 

 drawing) and Bulla ampulla 1 in the Severn drift implies as much. 



I can identify only two deposits in the West of Scotland with this 

 series — Garvel Park and Loch Gilphead, with perhaps Lochaber. 

 The presence of Rissoa cancellata and B. striatida (the latter only 

 known fossil elsewhere at Selsey), so far removed from their present 

 locality, is remarkable. The "head" over the Portland Beach and the 

 Crystalline Stalagmite above the Cave Bear breccia of Kent's Hole 

 correspond to this open-air earlier deposit. 



Hessle Gravels, etc. — As the first portion of the Interglacial 

 series culminated with the deepest submergence of the North and 

 North-west, so the second part commences with its re-emergence. 

 It is understood that depression is more pertinent to accumulation than 



1 Mr. Mackintosh, I think, is not very favourable to Molluscan evidence. I am 

 afraid he is hardly a fair judge, as he divides this species into two genera. 



