A Walk along the Glacial Cliffs of Killiney Bay. 17 



Here, incomplete, we must leave this hasty account of our 

 afternoon's walk. The half remains untold, and even from 

 what we have described we can form no connected and con- 

 sistent story ; clear only does it appear that at the time these 

 deposits which form its latest cliffs were accumulating, the 

 Irish Sea was not in winter open, tossed with swift waves, as 

 now, but ice-bound like the frozen regions of the north. 

 Whether, however, a great glacier displaced its waters and 

 filled its channel from side to side with massive ice as some 

 would have it, or whether its waters still maintained their 

 place, nay, even with extended depth and margins, but sealed 

 under a thick layer of ice, like Hudson's Straits in winter, and 

 traversed by fleets of icebergs sailing south in summer, these 

 and other hypotheses we do not now touch ; more facts are 

 wanted before definite conclusions can be reached, and with 

 facts so easily to be collected and ascertained, the wonder is 

 that we have not more inquirers into this fascinating branch 

 of science. 



PAl<^ONTOI,OGICAI< NOTES. 



(BY R. u,oyd praegkr.) 



Boulder Clay. — The boulder clay is everywhere highly fossiliferous. 

 The shells are almost invariably fragmentary ; bivalves are much more 

 abundant than univalves. Some of the fragments are highly polished on 

 both sides, with all the edges rounded ; a few are scratched ; but the 

 majority have sharp edges, and have not suffered very rough treat- 

 ment, as is strikingly exemplified by the fact that in some cases the 

 epidermis still adheres. The following is a provisional list of species 

 observed : — 



* (N.) Ostrea edulis. (N.) Tellina balthica. 



— Mytilus edulis. — Mactra subtruncata. 

 N. ,, modiolus. (S.) ,, solida ? 



Ext. N. Leda pemula. — Saxicava rugosa. 



(N.) Lucina borealis. — Corbula gibba. 



— Cardium edule. (N.) My a truncala. 



ji 



echinaium. • — Turritella terebra. 



(N.) Cyprina islandica. — Buccinum undaium. 



(N.) Astarte sulcata (aggr.). — Murex erinaceus. 



N. ,, compressa, var. striata. Ext. N ? Nassa, sp. 

 ( S. ) Tapes aureus ? N. Balanus tulipa-alba. 



* (N.) signifies that the habitat of the species is somewhat northern, 

 N. distinctly northern, (S.) somewhat southern ; and Ext. extinct in 

 British seas. The sign — signifies that the species is widely diffused both 

 north and south of Britain. 



