1883.] Mineralogy. 779 
phenomena in the region of the South Bavarian high plateau, and 
also in the Bavarian Alps,” to Dr. A. Penck, of the Munich Uni- 
versity. The work treats of the last glaciation cf Upper Bavaria 
and North Tyrol, of older glaciations in the same districts, and 
of the formation of the Upper Bavarian lakes. A complete de- 
scription of the effects of ice action in the defined localities, is 
given, also a comparison with those of North Germany and 
Scandinavia, and the concluding chapter has an able discussion on 
the causes of the Glacial epoch. At a recent meeting of the 
Geological Society of London, Mr. D. Mackintosh gave the 
results of observations on the positions of boulders relatively to 
the ground around and below them. His investigations were car- 
ried on near Llangollen (Wales) and at Clapham (Yorkshire) and 
his results are, that the average vertical extent of the denudation 
of limestone rock around boulders has not been more than six 
inches, and that this denudation has been ata rate of not less 
than an inch in a thousand years. This gives not more than 
6000 years since the boulders were deposited. 
Recent.—The Rev. A. Irving (Geological Magazine, April) gives 
the classification of landslips adopted by Herr Heini, of Zurich. 
These “ Bergstiirze” are either “ Schuttrutschungen ” or descents 
of. water-logged accumulations from the mountain slope into the 
valley, a movement which sometitnes produces striations simu- 
lating those of glacial action; “ Schuttstiirze,” or emptyings upon 
the valley below of loose material, accumulated in a minor val- 
ey on the mountain side; Felsschlipfe,” or loosenings of the 
upper strata, when the general dip is towards the valley, by the 
erosion of the lower part of the sides into a slope much deeper 
than the dip slope of the strata of the mountain above ; and 
“ Felsstiirze,”’ or the breaking loose from the sides of the moun- 
tain of huge masses of rock. 
MINERALOGY:' 
; Š ited by Professor H. CARVILL Lews, Academy of Natural Sciences, Phila- 
del to whom communications, papers for review, etc., should be sent. 
Amer. Fourn. Sc. and Arts, June, 1883. 
