28 Dr M. Sars on Shells from the Earlier and 
arctic species are found as fossils in Italy and Sicily (For- 
handl. i Vid. Selsk, ¢ Christiana, 1858, p. 78); and further, 
the very remarkable fact, that in both these seas perfectly 
identical species are found living which are absent on the 
intervening coasts of the Atlantic. Such are, Nephrops 
norvegicus (Cancer), L. Lotaabyssorum (Nilss.),( = Elongata, 
Risso. L.), Sebastes impertalis (Cuv.), and Macrourus (Lepi- 
doleprus) ccelorhynchus (Risso). ‘To these I have recently | 
(J. c. p. 86) added two shells discovered by me in the sea at 
Bergen, viz.—Cerithium vulgatum (Brug.), and Monodonta 
limbata (Phil.), whichare found living in the Mediterranean, 
but on none of the intermediate coasts between that sea 
and Norway. 
To explain, then, the presence of these species in the 
Mediterranean and in Norway, with their absence from the 
intervening coast, we must, as I have already elsewhere 
remarked (see Bemer lninger over det adriatiske Havs 
Fauna, Magaz. f. Naturv. 7 B. 1853, p. 395), suppose, 
either that nature, which has so often produced analogous 
but distinct species, in localities far remote from one ano- 
ther, has in this instance, created perfectly identical species 
at two so distant points, a fact of which we have absolutely 
no other instance ; or, which is far more probable, that the 
existence of these species dates from a period—viz., the 
Post-pliocene, when towards the east a connection existed 
between the Mediterranean and the North Sea, which at a 
later period was interrupted by the elevation of the Alps. 
In a paper since communicated to the “ Nyt Magazin,” 
Dr Sars distinguishes the fossil-bearing beds of the glacial 
formation into four kinds, different in age and constitution. © 
1. The older shell-beds, which lie at from 300 to 500 feet 
above the sea. Loose heaps of entire or broken shells, the 
bivalves seldom in pairs. The mass of shells sometimes 
pure, sometimes mixed with fine sand. 
These facts prove that such beds are of littoral origin, 
formed in bays, where their sheltered position preserved 
them from being swept away and scattered by the waves 
during the subsequent elevation of the land. That they 
