20 Dr M. Sars on Shells from the Earlier and 
Lekum in Edsberg. Height 220 feet. 
Here the shell-beds are of small extent and thickness. 
They lie in the upper part of the clay flat which extends 
all around. 
Littorina littorea (Turbo), L. LL. littoralis (Nerita), L. 
Mytilus edulis, L. 
Grorud near Christiania, 
In the sea-weed clay, which takes the place of the shell- 
clay. 
Tellina solidula, L. Saxicava pholadis (Mytilus), L. syn. 8. 
rugosa, 
Glaeng and Sarpen. Height 80 to 100 feet. 
Ostrea edulis, L. Pecten danicus, Chemn. _ P. opercularis 
(Ostrea), L. Cardium echinatum, L. Cyprina islandica 
(Venus) L., (often perforated by Cliona celata, Grant.) 
Astarte compressa, Mont.  Tellina proxima, Brown. 
Kaholmen near Drébak. Height 20 to 30 feet. 
Lowest clay. 
Tritonium despectum (Murex), L., syn. Fusus antiquus. Pecten 
maximus, L. Lima excavata (Ostrea), Gmel. Cyprina 
islandica (Venus) L. 
Oculina prolifera (Madrepora) L, (also in a mass of clay 20-30 
feet and upwards above the sea, south of Drébak). 
CLAY OF BOTH AGES, EARLIER AND LATER. 
Lower and Upper Foss near Christiania. 
Partly in the marl, interspersed with thin layers of sand ; 
partly in the overlying shell-clay. 
Turritella communis, Risso. Philine scabra (Bulla), Miill. 
Dentalium abyssorum, Sars. D. entalis, L. Siphono- 
dentalium vitreum, Sars. Ostrea edulis,L. Pecten islan- 
dicus, Mill. P.danicus, Chemn. PP. tigrinus, Mill. P. 
sinuosus, Turt. Arca raridentata, Wood, var. major, Sars. 
Nucula tenuis (Arca), Mont. Leda caudata (Arca), Don. 
L. pernula (Arca), Miill., syn. L. oblonga. Yoldia pygmea 
(Nucula), Miinst. Cardium edule, L. C, suecicum, Reeve. 
Isocardia cor (Cardium), L. Syndosmya nitida (Mya), Miill., 
syn. S. intermedia. Corbula nucleus, Lamk.  Saxicava 
arctica (Mya), L. 
