-'■i'2 The American Geologist. March, 1894 
few species, of ten with both valves united. We know small Pleistocene 
beds of lignite, with numerous identifiable plants, indicating a temper- 
ate climate, and elsewhere we see, as at Vogelsang, a Pleistocene chalk, 
tilled with flu viatile diatoms and shells, underlying a marine bed tilled 
with Cardium eduk, and Tellina baltica. All these beds are situated 
between two boulder-clays. I am far from saying that each sedimen- 
tary bed interposed between boulder-clays indicates an interglacial 
epoch; for I know, and have demonstrated, that such beds may be 
formed by subglacial waters. But I propose to take each observation 
of a consistent fauna or flora in a hundred or thousand specimens as a 
case of original deposition, and therefore, if it lies between boulder- 
clays, as a case of interglacial sediments, and if it lies at the base of all 
known boulder-clays, as a case of preglacial sediments. 
In England we have in preglacial time, ending the Tertiary and begin- 
ning the Quaternary era, the Forest bed and the Bridlington Crag. 
Similarly in Prussia there occurs a sandy bed with Dreissena polymor- 
ph^,, Valvata species, and the bones of Elephas.Rltinoceras. Bos,Equus, 
and Cervus tarn minx; and, above that bed, a clay with Yoldia arctica, 
Cyprina islandica (small variety), Astarte borealis,-Phoca {Tagophilus) 
grosnlandicus, and numerous bones of Gadus species. Thus attirst there 
was a fluviatile fauna of Sarmatian character, and then a marine fauna 
of Spitzbergen character. Next followed the Early Glacial (Altglacial) 
epoch, depositing a series of boulder-clays, with intercalated gravels, 
sands and clays, containing few organic remains. The few fossils which 
we have found here are not consistent, for in these ancient glacial de- 
posits teeth of Elephas occur near shells of Yoldia., and Yoldia is mixed 
with Dreissena or Va.lv at a, but neither Cardium nor Tellina, Mactra, 
Nassa nor Cerithium are found in the preglacial and ancient glacial 
strata. The later named species are found only in interglacial and later 
glacial strata. 
The interglacial series is marine near Bremen, Hamburg, Kiel, and in 
Denmark, also in the greater part of Prussia; but it is fluviatile near 
Konigsberg and Memel, likewise near Berlin, and at Lauenburg on the 
Elbe. The interglacial marine fauna of Prussia is composed of Car- 
dium edule, C. echinatum. Tapes virginica, Cyprina islandica (larger 
variety). Tellina baltica, Maetra subtruncata, Mytilus edulis, Scrobicu- 
laria piperata, Mya species, Corbula gibha, Nassa reticulata, Cerithium 
species, Littorina litorea, and Scalaria communis. Never is Yoldia 
arctica found in these beds, which have yielded many thousand speci- 
mens of these more temperate species ! All the animals and plants of 
this series indicate a moderate climate like that of the present time, 
but perhaps of more insular character. 
Then follows the Late Glacial (Jungglacial) series, composed, like the 
Early Glacial, of boulder-clays, with intercalated gravels, sands and 
clays. These younger gravels are rich in organic remains, but the fos- 
sils are mixed, representing all known preglacial and interglacial beds. 
Very commonly we find Yoldia arctica. together with Cardium, Dreis- 
sena and Elephas, showing clearly that these fossils must be regarded 
as derived from older beds. 
In conclusion. I think it certain that northern Germany had an inter- 
glacial epoch. The same epoch, with terrestrial fossils, is indicated in 
Great Britain, Switzerland, Austria, northern Italy and along the 
Rhine. Perhaps we may see proofs of its existence also in some fossil- 
iferous beds found recently near Moscow and in Scandinavia. Accord- 
ingly I ask the fellows of the Geological Society of America to give some 
place to this short communication in forming your theories of the Ice 
age in Europe. 
56'. The Madison type of drnnilins. Warren Upham, Somerville, 
Mass. (Read by title.) The Capitol, University and Observatory hills 
in Madison, Wisconsin, are drumlins of a peculiar class or type, con- 
