510 REPORT— 1893. 



genns is represented by one or other of its species in every part of the 

 tropical and temperate zones.' ' Oypsina globulus, again, is chiefly found 

 * in the coral reefs of warm latitudes,' though ' small examples are 

 occasionally met with on the northern and western shores of the British 

 Islands.' ^ The varieties of Truncatulina variabilis also, though ' not 

 entirely confined to shallow water, are commonest at the shallow margins 

 of sub-tropical and temperate seas.' ^ 



These species are comparatively rare in our Scottish clays, and it 

 seems interesting to note their occurrence at Clava, where the list, as a 

 whole, is of moderate dimensions. 



It may also be pointed out that there are five species of Foraminifera 

 in the list from section 160 yards SW. which were not met with in the 

 main section ; but this is of little consequence, as, if two parcels of clay 

 'he taken from the same bed, only a few feet apart, they will seldom be 

 found in all their details exactly alike. 



D. R. 



Additional Heports and Hemarhs. 



A separate examination of the ' main pit ' was made by Mr. 

 T. F. Jamieson, LL.D., of Ellon, who has furnished the Chairman with 

 the following observations as the result of his visit: — 



' The extreme thickness of the dark blue clay is about 16 feet. The 

 lowest, 4 or 5 feet, is studded with small pebbles, many of which seem 

 water-worn. The shells are by no means numerous — more scanty than I 

 expected — and seem to be most frequent perhaps at a depth of about 

 2 feet from the top. At least the Littorina littorea appeared to be got 

 oftenest there, and, being a stout shell, it is generally in better preserva- 

 tion tlian the others, most of which are very decayed and tender, so that 

 they will hardly bear touching. The epidermis, however, is quite visible 

 on most of them, so that there is nothing to countenance the notion that 

 the shells have been ice-borne to then- present location. The uppermost 

 10 or 12 feet of the blue clay is almost quite free from stones, and is a 

 pure silty clay or mud such as might be expected to form on the .sea- 

 bottom. It is not at all of the nature of the boulder clay such as we see 

 in Caithness, and I think the probability is that it has been formed where 

 it lies. Had it been transported in a mass from some great distance by 

 the glacier, it would have been more dislocated, and would not occupy 

 such a regular horizontal position beneath the boulder clay, for it is 

 traceable along the base of the bank to a distance of 160 yards south- 

 westwards at about the sfime level. 



' I think, however, that the pressure of the deep mass of boulder clay 

 above, with that of the superincumbent moving glacier, must have 

 occasioned some change in the texture of the clay by consolidating it, 

 and probably causing some degree of movement in its mass. This would 

 account for the crushing of some of the shells and the obliteration of the 

 lamination of the clay and want of any distinct stratification. 



' My idea is that after the deposition of the blue clay there had been a 

 subsequent development of land-ice on a great scale.' 



T. F. J. 



' H. B. Brady, ' Challenger ' Re2)ort, vol. ix. 

 ■ Ibid. » Ihid. 



