Summary. 
During the winter 1899—1900 two borings were performed 
near Tønder (Tondern) in Sleswick; on that occasion marine pleistocene 
deposits, containing a rich, warm fauna, were found in the depths 
of 14,8 and 18,8 m. under the surface and of a thicknéss of c. 10 m. 
These marine deposits were covered by fluvioglacial sand and rested 
upon beds of boulder clay and glacial sands. (In later time several 
other borings in the same part of the country have further established 
the interglacial age of these marine deposits). The result of these 
borings near Tønder was published by P. Harder (Meddel. Dansk 
geol. Forening. Kbhvn. 1900. Nr. 6.) and, assisting him in the 
determination of the mollusca, I found that the most remarkable 
species was a big form of the genus Tapes, which I then regarded 
as an unusually great form of T. aureus Gm. Later on, in the 
course of my investigations of certain interglacial marine deposits 
in Denmark, the Netherlands and Northern Germany, which I gave 
name of the Eem-deposits (see: Danmarks geolog. Undersøgelse 
II. Række Nr. 17. 1908) I found that this great extinct species, 
which hitherto had been known from the Netherlands and West 
Prussia under the determination of Tapes virgineus L., was the 
most characteristic fossil of these Eem-deposits, and I gave it the 
name 7'. aureus var. eemiensis, considering it as a variety of the 
T. aureus. The diagnosis is reprinted on p. 288. 
On my journey in England 1909 I looked in vain for this 
species among the mollusca from the Crag deposits (perhaps some 
fragments from the Pliocene St. Erths beds might belong to this 
species, but the material at hand was very badly preserved); but 
having made acquaintance with the work of Cerulli-Irelli: 
Fauna malacologica mariana. Palaeontographia italica. Vol. 14. Pisa 
