196 The Irish Naturalist. 



riebeckite granophvre, and vein quartz, many thoroughly 

 rounded. One inch above its junction with the boulder clay 

 the deposit is cemented into a hard conglomerate for a thick 

 ness of several feet. This section corresponds to that which 

 lies near the road on the other side of the river. As we pass 

 up the river-bank along this section, the boulder gravels 

 present us with an exceedingly complex succession of deposits. 

 Not far from the section just described, we observe above 

 the boulder clay a bed of fine sand some five feet thick, well 

 laminated, and containing numerous fragments of Tellina 

 balthica, Astai'tc siilcata, A. borealis, Leda per?iula, and other 

 species of marine shells. This is succeeded by fourteen feet 

 of boulder gravels, of the usual character in the lower half, but 

 in the upper half formed of an irregular layer composed 

 almost exclusively of fragments of slate. Above this is ten 

 feet of exceedingly fine laminated sand. The boulder gravels 

 contain blocks of granite, some three feet long by one foot six 

 inches thick. One of these is of particular interest since it 

 contains spodumene, and closely resembles the granite which 

 occurs at Ballycorus Hill, two miles to the N.W. ; granite con- 

 taining spodumene was also at one time found in the quarry at 

 Killiney, four miles N. The boulder gravels continue with 

 varying character some distance up the stream. The bed 

 characterised by slate fragments thins out in lenticular fashion 

 within a short distance. Near its termination the slate frag- 

 ments were observed lying parallel with the oblique lamination 

 which there characterises the deposit. A remarkable feature 

 of this bed here is the presence of numerous included rolled 

 fragments of red boulder clay. The occurrence of great frag- 

 ments and pebbles of boulder clay is a noticeable feature of the 

 boulder gravels near their junction with the boulder clay. The 

 occurrence near the base of the boulder gravels of a distinct 

 layer of pebbles to which pebbles of boulder clay contribute is 

 also to be observed. We need not refer again to the varying 

 character of the boulder gravels at this place except to observe 

 that the fine sand replaces the gravels and pebbly beds until 

 thirty feet of finest sand appears, extending down to within 

 twelve feet of the river. A little further up the valley pebbly 

 boulder gravels again come in, and eventually entirely replace 

 the sand. 



As regards the boulder clay, its lamination may be frequently 



