1892-93.] 521 



species being Astarte sulcata var. elliptica, A. compressa var. 

 striata, and Tellina balthica. 



Below the clay is 20 feet of gravel. In its upper portion the 

 deposit is coarse, somewhat reddish in colour, and with a slight 

 admixture of clay ; the lower portion is very fine and clean, 

 with layers of clean grey sand. The bed is stratified somewhat 

 irregularly, but more or less horizontally. At one spot, beside 

 a waterfall, a bed of fine red clay, 5 feet in thickness, is suddenly 

 intercalated with the gravels. The pebbles in the gravel are 

 mostly of trap, chalk, quartz, and flint. The larger flints are 

 often more or less broken, having chips and flakes knocked off 

 them, which also occur in the gravels, still looking quite fresh. 

 The larger flints frequently show two fractures — an older series, 

 the faces of which are now thickly encrusted ; and a newer series 

 with uncoated faces, perhaps formed at the time of the deposi- 

 tion of the gravel. Some of the flint chips are encrusted, others 

 quite free from crust. Shells, generally fragmentary, are abun- 

 dant in the gravels, and they are rarer and more fragile in the 

 upper portions of the bed, probably on account of its coarser and 

 more open nature, which affords less protection from the 

 influences of air and water ; but in the fine lower gravel also 

 the strongest shells, such as Astarte, are very frequently frag- 

 mentary, and appear to have been broken prior to, or during 

 deposition. Single valves only were observed, and the whole 

 aspect of the bed and of its fauna is that it is an ancient sea- 

 beach. The layers of sand appeared devoid of shells. The species 

 observed in the gravels were as follow : — 



Puncturella noachina, vr. Astarte sulcata var. elliptica, vc. 



Buccinum undatum, f. A. compressa var. striata, vc. 



Trophon truncatus, vr. A. borealis, vr. 



T. clathratus, vr. Tellina balthica, c. 



T. clathratus var. gunneri^ vr. Mactra subtruncata, c. 



Pleurotoma trevelyana, vr. Mya truncata, vr. 



Mytilus edulis, r. Saxicava rugosa, vr. 



Leda pernula, f. Balanus tulipa-alba, c. 



