/S*. G. Perceval — Discovery of PaJceacis cimeata. 267 



us an idea of the passage from the Miocene period, with its Taxodiiim, 

 beech and plane forests, to the mer de glace of the present period. I 

 have not succeeded in doing that ; but I am persuaded that by future 

 complete examination of the peninsula which separates Ice from 

 Bell Sound, we may gain data for answering the interesting questions 

 relating to this point. 



Before concluding this account of the Geology of these regions, I 

 wish to notice the strata which are believed to show that Spitzbergen, 

 during a not very remote period of time, of which Geology gives 

 evidence, enjoyed a climate better than the present. At various 

 places on Spitzbergen, at the bottom of Lomrae Bay, at Cape Thord- 

 sen, in Blomstrand's strata at Advent Bay, there are found large 

 and well-developed shells of a bivalve Mytilus edulis, which is not 

 now found living on the coasts of Spitzbergen, though on the west 

 coast of Scandinavia it everywhere covers the rocks near the sea- 

 shore. These shells occur most plentifully in the bed of a river 

 which runs through Eeindeer Yalley at Cape Thordsen. They 

 are probably washed out of a thin bed of sand at a height of 

 about 20 or 30 feet above the present sea-level, which is inter- 

 sected by the river. The geological age of this bed cannot be 

 very great, and it has clearly been formed since the present basin of 

 Ice Sound, or at least the greater part of it has been hollowed 

 out by glacial action.^ 



XI. Becent formations. — Glaciers and loose earthy layers formed 

 by glaciers. 



The interestiug circumstances connected with these formations 

 deserve their own chapter, the more so as they have a peculiar bear- 

 ing upon the explication of the loose layers in Sweden. But from 

 want of time, at present, I must defer this till another occasion. 



VI. — On the Discovery of Pal^acis cuneata, Meek & Worthen, 



IN Carboniferous Limestone near Henbury, Bristol. 



By S. G. Perceval, Esq. 



THE above form I found a year or two ago in the Encrinital Lime- 

 stone forming the upper bed of the Lower Limestone Shales which 

 occur on the south side of Combe Down (overlooking Combe House), 

 near its western extremity. I have also traced it in an outcrop of 

 the same limestone in the plantation on the north side of Kings- 

 weston Down, near its western extremity. At both these localities 

 the fossil is associated with Zaphrentis PhUlipsi, a small coral which 

 is characteristic of the bed. Palceacis probably also occurs in the 

 corresponding beds exposed in the Avon section, and elsewhere ; 

 but though tolerably abundant, is not likely to be observed, on 

 account of its small size, except where the rock is well weathered. 

 The accompanying are sketches of two specimens from Combe 



1 Compare : Miocene Flora und Fauna Spitsbergens, p. 23. With reference to 

 the vegetable remains from these strata described by Heer, it may herebe stated, 

 that since Heer's work was published, BeUila nana has been found growing on the 

 north-east shore of Coal Bay. 



