STftATIGliAPHICAL SEMES. 
155 
ancient river-deposits and from certain bone-caves. The Recent 
or Historical period is represented by a series of deposits now 
in course of formation on the sea-bottom around Britain, as also 
by samples of peat, modern conglomerates, stalagmites, &c. 
It will be noted that the stratigraphical series is thus brought 
to an end exactly opposite to the starting-point in the 'first Wall 
Case containing the collection of archa?an rocks. A detailed 
handbook to the Rock Room is in course of preparation, and 
consequently this department of the Museum has been only very 
briefly described in the preceding pages. 
