480 Chronicles of Science. | July, 
and their subdivisions. He bases his arguments upon the percentages 
of species common to the formations next in time to one another, as 
shown in tables perfectly bewildering in their complexity, and accord- 
ing as he finds them great or small, aided by stratigraphical consider- 
ations, so does he infer the existence or non-existence of an uncon- 
formity or of a break between them. 
The two principal breaks shown to exist are—l. That between the 
Bunter and Keuper strata—represented on the continent by the Mus- 
chelkalk and the St. Cassian beds; and—2. That between the Oolitic 
and Cretaceous formations, which is represented, wholly or in part, by 
the Wealden and Purbeck beds. 
In conclusion Professor Ramsay enunciates a general principle 
which he has inferred from his researches on breaks in succession, as 
follows :—“ Making, as we can often do, all liberal allowances for diver- 
sities of marine and terrestrial conditions, I cannot resist the general 
inference that, in cases of superposition, in proportion as the species are 
more or less continuous, that is to say, as the break in life is partial or 
complete, first, in the species, but more importantly in the loss of old and 
the appearance of new allied or unallied genera, so was the interval of 
time shorter or longer that elapsed between the close of the lower and the 
commencement of the wpper formation ; and so it often happens that 
strata a few yards in thickness, or, more notably still, the absence of 
these strata, may serve to indicate a period of time as great as that 
represented by the vast accumulations of the whole Silurian series.” 
Let him now calculate the age of the world who can. 
2. Herr von Koenen’s short paper, ‘“‘ On the Oligocene Deposits of 
Belgium, Northern Germany, and the South of England,” is the result 
of a visit made by the author—a young German geologist—to the Isle 
of Wight and Hampshire, during which he managed to show, by means 
of fossils collected by himself, that certain strata known as the Middle 
Headon beds, which contain freshwater shells in the Isle of Wight, 
but marine fossils at Brockenhurst, belong to the Lower Oligocene 
formation of Germany. Of course Herr von Koenen advocates the 
adoption of Professor Beyrich’s term “ Oligocene,” on the propriety, 
or rather the necessity, of which opinions are divided in England, but 
the question is too complicated to be discussed in an abstract, 
However, the paper shows us that in that often-explored region— 
the Isle of Wight and Hampshire—the young geologist may still be 
rewarded by making discoveries of interest. 
3. In his paper on “Supposed Glacial Drift in the Labrador 
Peninsula, Western Canada, and on the South Branch of the Saskat- 
chewan,” Professor Hind describes phenomena, some of which occur 
on so grand a scale that, paradoxical as it may appear, they would be 
overlooked by the ordinary observer. Many of these phenomena have 
resulted from the operation of the forces that produced the present 
physical configuration of the surface. Of this nature are the terraces 
so abundant in the line of country between Lake Winnipeg, and the 
Grand Coteau de Missouri, in which region occur several precipitous 
escarpments facing North or North-east, the opposite face of the 
mountain always consisting of gently sloping plateaux separated by 
